P1444 / P0325 - Evap cannister and valve ???

[Kennyp]

Got a 99 Pathfinder that is throwing the famous P1444 code and while I don't think it's related also the P0325 knock sensor code.... Have new knock sensor and plan on doing the bypass....

So here's my thoughts... If you look up a Evap Cannister they run $150+ for the pathfinder, but you. Can buy one for the same yr Maxima for $30 bux

They look the same with the only exception being the mounting points.... Has anyone ever tried using the Maxima one? And just made new mounting hardware? Seems simple enough.... Thoughts?

Link to the Pathfinder unit:


http://www.partsgeek.com/gbproducts/MC/ ... 7433949932


Link to the Maxima unit:

http://www.partsgeek.com/gbproducts/DC/ ... 7433949932

[barnaclebob]

For $120 savings I'd give it a shot based on the pictures. The maxima unit seems to be flipped over but maybe some standoffs or a homemade bracket will do the trick.

[atraudes]

Holy cats, report back on your findings if you go with the Maxima unit!! That's a heck of a price difference and other folks here would be extremely thankful if you had found a cheaper alternative.

[Hawairish]

I'd be willing to confirm that! My 98 Frontier is facing P1444 right now, and I started fixing repairing things just over the weekend. The charcoal from the canister worked its way all the way up to the Evap solenoid and clogged it. What a PITA to clear the lines. I went out and bought some new charcoal, figuring to rebuild the canister because the cost of a replacement is ridiculous.

RockAuto says there's cross-compatibility between Frontier and Pathfinder canisters (among others models), particularly a 99. RA also says the vent solenoid for these and the Maxima (same years-ish) is the same. I'll have to take closer look at the canister photos (am currently on my phone), but looks like it would be pretty easy to adapt. Fortunately, I've also already got my canister down.

[Hawairish]

For $120 savings I'd give it a shot based on the pictures. The maxima unit seems to be flipped over but maybe some standoffs or a homemade bracket will do the trick.

I think you're right. The body of the canister appears to be identical, as does the end piece with the two mounting tabs. The port face is the same, just mirrored.

Here are the links from RockAuto with a couple more pics...
98-00 Frontier, 98-01 Pathfinder: http://www.rockauto.com/en/moreinfo.php ... 93&jsn=437
97-98 Maxima: http://www.rockauto.com/en/moreinfo.php ... 03&jsn=493

If the mounting pattern is the same, all you'd need is some sort of spacer and longer bolts to account for the lowered mounting tabs.

Having taken a deeper look into this, I'm going to order one and save myself the trouble of rebuilding the canister. Just can't believe how expensive these things are when you consider that it contains the same crap (charcoal and filters) that you can basically buy at PetSmart.

Great find, kennyp!

[Kennyp]

Awesome... Let us know how it works out. Im planning on doing my daughters too.. Just really csnt afford to spend the money jf it doesnt work... Tight budget right now...

Thx

[barnaclebob]

I'd think you be able to zip tie or hose clamp it in place if absolutely necessary.

[Hawairish]

So...the image hosting site I use is down right now, so I'll post up pictures later. Here's what I can tell you now...

I bought the Standard Motor Products CP3106 canister in the link above. My 98 Frontier canister is stamped 14950-1S700, which has been superseded by p/n 14950-1S717 (which also replaced 14950-1S710, 14950-1S715, and possibly others). The SMP equivalent is CP3090 and is listed as fitting several Nissan models, but in particular 98-01 R50 and 97-00 QX4.

As suspected, the dimensions are practically identical, and the port side of the canister is in fact just a mirror image. The body, rear plate, port diameters, and mounting pattern are all the same. The vent valve fits perfectly. Because the body is flipped upside down for the Maxima canister, it moves the two rear mounting tabs down about 0.75". I plan to use some square aluminum tube I have sitting around to make spacers.

For my application (I haven't mounted it up yet), I will need to reroute the vent valve wiring harness, since the connector will be a few inches farther away. Not sure if this holds true for R50/QX4, but I could probably take a look at the wiring on my truck and make a guess. It looks like the tubes will reach, though I'm planning to replace my hoses anyway. The $120 savings affords $5 in hoses.

Pictures to follow...

[Hawairish]

[fueler]

For knock sensor code, reset it and see if it comes back. Knock sensor is easy to set off on Nissans, I just ignore it.

For the canister valve, I took the valve off and cleaned it with carb cleaner - that did nothing for me. Then, I took the valve off and shook it, it didn't make any noise... the inside was gunked up. I banged it on the ground and now it clicks back and forth when you shake it. Re-installed, no more code.

I hope your fix will be as easy as mine was.

[Buzzman]

For the canister valve, I took the valve off and shook it, it didn't make any noise... the inside was gunked up. I banged it on the ground and now it clicks back and forth when you shake it. Re-installed, no more code.

Where is the canister valve exactly? Is it under the back bumper where the canister is?
I've had the same evap codes for years, and just ignore them.
Unfortunately, my truck (when I get the hood open...lol) is due for a smog test this spring, so that may be a problem.

[Hawairish]

The canister (vent) valve is the one shown in the last picture I posted. Though, I think if that is faulty, it would throw a P1446? P1444 is for the purge solenoid in the engine bay I believe, though the troubleshooting steps in the FSM do eventually have you check the vent valve.

[yeldogt]

You need to have a low personal hourly rate.

[Hawairish]

Huh?

[fueler]

P1444 is for the purge solenoid in the engine bay I believe

Yup, P1444 is canister vent valve under the hood, not the one in the bumper.

[yeldogt]

You need to have a low personal hourly rate.

IE: My time is not worth the trouble .... especially if it does not work .. or fails too soon. Often the case .. ends up costing more.

I always look at DIY projects as doing it correct for less. Find I have longer long term success buying the correct high quality part when I wrench my cars. The vast majority of repairs I do to my cars are "one off" -- I'm fixing something that I have never done on this model and will never do again. If you go about fixing something correctly -- you tend to have success .. it stays fixed and you don't introduce a question into the equation when something related pops up. So many threads on auto forums where people can't understand a problem after fixing something -- either by throwing parts they think are bad or using parts of questionable quality. They don;t know it the original problem is still around or one they just installed.

IMO - It's so easy to get the correct part, save money, fix the problem and enjoy doing it ... it's not about saving the most money. I love finding quality cross referenced parts -- finding the OEM Tstat from my MB and saving 75 bucks -- and doing it myself .... so I saved $300.

So .... I normally get the OE part from an online dealer. They always fit -- high quality .. I'm a happy wrencher. I'm fine with getting something like a Zimmermann rotor -- if available and represents a real saving over the OE.

I find this works for cars -- homes .. employment decisions and relationships.

[barnaclebob]

You need to have a low personal hourly rate.

IE: My time is not worth the trouble .... especially if it does not work .. or fails too soon. Often the case .. ends up costing more.

I always look at DIY projects as doing it correct for less. Find I have longer long term success buying the correct high quality part when I wrench my cars. The vast majority of repairs I do to my cars are "one off" -- I'm fixing something that I have never done on this model and will never do again. If you go about fixing something correctly -- you tend to have success .. it stays fixed and you don't introduce a question into the equation when something related pops up. So many threads on auto forums where people can't understand a problem after fixing something -- either by throwing parts they think are bad or using parts of questionable quality. They don;t know it the original problem is still around or one they just installed.

IMO - It's so easy to get the correct part, save money, fix the problem and enjoy doing it ... it's not about saving the most money. I love finding quality cross referenced parts -- finding the OEM Tstat from my MB and saving 75 bucks -- and doing it myself .... so I saved $300.

So .... I normally get the OE part from an online dealer. They always fit -- high quality .. I'm a happy wrencher. I'm fine with getting something like a Zimmermann rotor -- if available and represents a real saving over the OE.

I find this works for cars -- homes .. employment decisions and relationships.

That's a great philosophy that you'll have until you need to replace a MAF. $400 for the pathfinder part#, $135 for the maxima part#. Otherwise they are the exact same. In for the OP in this thread a $120 savings for the exact same part with minor modifications. Not sure why you have to pontificate about how using a slightly different part means someone doesn't value their time.

[Hawairish]

That's a great philosophy that you'll have until you need to replace a MAF. $400 for the pathfinder part#, $135 for the maxima part#. Otherwise they are the exact same. In for the OP in this thread a $120 savings for the exact same part with minor modifications. Not sure why you have to pontificate about how using a slightly different part means someone doesn't value their time.

Well said.

Going way off topic, since that's where we've been dragged...

Being a "happy wrencher" doesn't exclude the need to be a "resourceful wrencher" and a "prideful wrencher". This topic wasn't about being cheap, either by cost or effort. It seemed about being resourceful and questioning the market to find an alternative solution, but it really doesn't even matter the real reason. The OP proposed a "what if" scenario and laid out some logic, and someone (me) was more than willing to confirm it, especially considering I was conveniently already facing the same issue (which is now completely resolved by this approach, I might add).

There's a time and place for using original or aftermarket replacement parts, versus substitute (i.e., non-application) parts...except if I ran a shop (which I don't). Perhaps the value of our trucks do not warrant a $150 part when a similar and seemingly identical-in-nearly-all-ways-that-matter $30 part will do with trivial modification (or in this case, some extra preventive maintenance by replacing old hoses with new, but slightly longer, hoses).

I'm blown away why such a part even costs 5x more, and you should be, too. I'll risk buying this alternative part and returning it if I don't think it will work before I ever play some game of supply-and-demand BS. But, if you want to spend 5x the price for what appears to be the same part, without questioning both worth and value, paying some excessive price to (usually) guarantee fitment and some presumptive quality assessment, then awesome...you're totally entitled to, and you're exactly what big business wants in a customer.

By the same token, lifted R50 owners now have <$30 front and rear brake line solutions when other companies want $100+ for custom extended brake lines that are unnecessarily stainless steel. That's because guys like me do this exact type of thorough research, find some suitable OE solutions, have the nuts to test them out, and are willing to take a small financial loss should it not work, just so they can willingly spread the word to the community about how to make it work. Ask me about how well my R50 stops with WD21 rear disc brakes and Rogue and Frontier brake lines (hint: even with cheap pads, it's better than stock).

[fueler]

just bang the part on the ground

[yeldogt]

I always check the cost of the OE part, at an online dealer -- that's my benchmark. Next comes finding the OEM part -- if possible (harder with Japanese cars) If I'm still annoyed at the cost I see if any quality OE manufacturers are making the part -- Example would be Zimmermann rotors for the front of the 4x4 Pathfinder. I have no problem using a cross reference --- or buying a MAFF and switching the actual sensor to the old body (quite common with MB's). I don't use most true aftermarket parts and I don't hack my fixes .. correct. I'm resourceful in that I get my cars fixed properly .... usually the first time.

Between my personal and company cars -- I have about 15 at any given time ... its been this way for over 25 years, some are new and under warranty .. others are old like the pathfinder (Have owned three 02 LE's) .. so I have some history with keeping and maintaining cars for long periods at the lowest cost and fewest problems. I do value my time .. yes .. it's valuable. My experience is that the other way does not produce the same results.

[Hawairish]

I always check the cost of the OE part, at an online dealer -- that's my benchmark. Next comes finding the OEM part -- if possible (harder with Japanese cars) If I'm still annoyed at the cost I see if any quality OE manufacturers are making the part -- Example would be Zimmermann rotors for the front of the 4x4 Pathfinder. I have no problem using a cross reference --- or buying a MAFF and switching the actual sensor to the old body (quite common with MB's). I don't use most true aftermarket parts and I don't hack my fixes .. correct. I'm resourceful in that I get my cars fixed properly .... usually the first time.

Between my personal and company cars -- I have about 15 at any given time ... its been this way for over 25 years, some are new and under warranty .. others are old like the pathfinder (Have owned three 02 LE's) .. so I have some history with keeping and maintaining cars for long periods at the lowest cost and fewest problems. I do value my time .. yes .. it's valuable. My experience is that the other way does not produce the same results.

This is fine and all, but ultimately off topic. You presented an unsolicited opinion and didn't provide any relevant insight to the OP's question.

[yeldogt]

How and why unsolicited? -- someone comes on speaking of a code that's not directly connected to the Evap tank .. and then people want to replace it? Normally the tank will be leaking and you will get another code. The valve is not even at the tank ... and the other vent valve .. at the tank usually throws the open circuit when it does fail? The cheap aftermarket valve has a history of failing.

Fix what is wrong with the car -- don't throw parts at something. The evaporation tank can be filtered -- and will work if it's not cracked.

Sometimes all those valves need is a good cleaning ...... The tank valve needs to be replaced if you get that one and the wires are intact. ... unfortunate they fail and no real good replacement is available .. it's an easy $80 buck fix.

So... you tried to rebuild you tank ... then ordered another tank? Because your tank threw dirt into a valve ...

[Hawairish]

How do you figure the P1444 is not related to the EVAP tank? Did you look at the FSM and check the troubleshooting steps? Sure as hell, there are P1444 diagnostics steps that involve...yep, checking the evap canister.

Now, kennyp doesn't say what he's tried, or how he reached the conclusion, but it doesn't even matter. He didn't ask about that at all. You made the assumption he was just throwing parts at a problem you apparently don't even understand (me thinks you've made the same assessment about me, too, and I've probably done more one-off jobs than whatever you've done on your fleet). Fact is, he did enough research to realize that a Maxima canister sure does look a lot like the one he needs and costs 1/5th the price, then wondered if anyone else made the same realization.

Now, let me tell you how an EVAP canister IS related to P1444 (aside from the obvious mention in the FSM that you didn't read). P1444 says that the EVAP purge solenoid is malfunctioning. And maybe it truly is and just simply needs to be replaced. Perhaps the o-ring on the solenoid failed, allowed moisture in the solenoid, which corroded the piston...a possibility. But then, you follow the FSM diagnostic procedure and realize that you get to the point where you should remove it for further inspection and troubleshooting. So you take apart the hoses, remove the valve, and immediately realize that the most obvious reason that it's throwing a code is because THE *$&@*&#!%# EVAP CANISTER FILTER FAILED AND ALLOWED CHARCOAL GRANULES TO TRAVEL FROM THE REAR OF THE VEHICLE ALL THE WAY UP THE LINES, INTO THE ENGINE BAY, AND INTO THE EVAP PURGE SOLENOID, ULTIMATELY PREVENTING IT FROM OPENING AND CLOSING PROPERLY.

And that is how it's related. It did not just "throw dirt into a valve", no matter what your ASE Certification in Internet Mechanics has taught you...it clogged the solenoid and the entire damn line with charcoal butt nuggets. Oh, and this isn't unique to Nissans.

Again, doesn't matter if kennyp reached this conclusion or not. He didn't ask you how you would solve this problem.

So, what do you do next? Well, you continue not being an internet mechanic and act like a "resourceful wrencher" by taking apart the solenoid to see if you can salvage a part and save $70. (The same $70 that you would've put towards a new solenoid to not solve the problem.) Comes to find out, a pair of pliers and a toothpick is all it takes to a easily disassemble AND repair an electromagnetic valve that basically can't fail under normal conditions considering it has one moving part and primitive circuitry...the same primitive technology you might expect from an 18-year old OEM solenoid that came with the truck and still works fine when charcoal isn't lodged inside it. SCIENCE!

Then, you clean out the hard lines doing whatever it takes (in my case, a vacuum, compressed air, a copper wire to poke through some charcoal build-up in the hard lines that the vacuum and compressed air can't budge, and eventually a fluid flush, before changing some old crusty hoses as while-you're-at-it maintenance). Then you figure out a solution for the failed EVAP canister...which, again, was the root cause of a P1444.

Enter kennyp. He makes a brilliant observation that requires little effort to research and could save $120 bucks, just like that, with trivial adjustment.

That all said, I did not NEED to rebuild a tank BECAUSE the OP suggested an alternative approach that appeared sensible and was worth a shot. (As opposed to your anecdotal story about Zimmermann products...I mean, do they make an EVAP canister or something, and do we actually give two s*** who makes the EVAP canister or that it's aftermarket and somehow aftermarket is inherently weak considering it's in all likelihood based on the original product specs sold to companies after some limit of exclusivity by the original parts manufacturer imposed by the vehicle manufacturer?) It was far easier and cleaner to try than cutting open the canister, replacing the filter and charcoal, and re-sealing the unit...which would probably cost more than $30 of my time, but would still be far less than $150.

So look, you do whatever you wanna do with your time and money. Keep it to yourself unless asked. My wallet thanks my efforts and kennyp's suggestion that saved me $190. I'm out $30 when you'd be out $220.

Now, what have you contributed to this conversation other than your unsolicited opinion?

[fueler]

How do you figure the P1444 is not related to the EVAP tank? Did you look at the FSM and check the troubleshooting steps? Sure as hell, there are P1444 diagnostics steps that involve...yep, checking the evap canister.

Nissan has 13 steps in the "FSM" service manual. Step 1 is "check the damn purge valve." The evap canister is in very last place on the list...

If the FSM says step 1 is check purge valve, then start with the purge valve. These flowcharts are made to be most efficient when read from top down, not from the bottom up.

What Yeldog is trying to say is, replacing the evap canister with a $130 Nissan Maxima version, with zip ties and double sided tape, is borderline crackhead behavior... but hey, its your money

[yeldogt]

Hawairish: you need to go into the bathroom and read your post -- while looking in the mirror. Tell me how it sounds/looks -- really nasty way to deal with someone that you don't agree with.

I come here trying to help -- Have 15 years with these vehicles and many more with Nissan. Take it for what it is ...


The fix for the problem is to first follow the code --- The code points first to the valve ...... possibly clean the valve (I always try and clean unless previous knowledge tells me it does not work). The lines and the hoses are a different matter and are mitigated by replacing or cleaning depending on rubber vs metal.

The tank is last -- and normally does not need to be replaced .. unless cracked. I understand all about the canister and it's contents.

I'm only going through all of this so others understand your system is not correct -- and you don't understand my post.

[Hawairish]

Sure man, I'll do exactly that when you step down from your podium, stop lecturing people about throwing parts at problems you don't understand, giving your unsolicited opinion on how other people should spend their time and money, and not actually helping anyone with your anecdotal, passive aggressive nonsense.

In my very first reply, I set the conversation by saying I had the same problem code and confirmed that the EVAP canister was the root cause, for the reason I've now repeated. Did you miss that? Clearly you did, otherwise you wouldn't have spewed this out at me:

[...]someone comes on speaking of a code that's not directly connected to the Evap tank .. and then people want to replace it?

Wrong. You made assumptions about how the OP reached his conclusion without even finding out.

Normally the tank will be leaking and you will get another code. The valve is not even at the tank ... and the other vent valve .. at the tank usually throws the open circuit when it does fail?

Wrong. It would be abnormal for the tank to leak, and of course it would throw one of several other codes for several other reasons...just not P1444 which we identified from the start. There's no degree of "normalcy" when a system fails. It's expected that some components may deteriorate and need repair or replacement, but failure is not normal.

The cheap aftermarket valve has a history of failing.

Do they? Have you been researching this? Do you have proof? Did anyone even say anything about having an aftermarket valve? Did anyone even say the (or a) valve had failed? Did we only start talking about aftermarket anything and their quality because you brought it up about your purchase history and buying pattern?

The tank is last -- and normally does not need to be replaced .. unless cracked. I understand all about the canister and it's contents.

And as clearly proven here, it needs to be replaced when the charcoal filter gives up the ghost and clogs the lines and EVAP purge valve. I don't think you understand that because I've said it three times now.

Seeing as your first post on this discussion was this non-contributing ambiguous brain fart, which also struck a chord with another member:

You need to have a low personal hourly rate.

...I don't see how you can reasonably say this:

I come here trying to help -- Have 15 years with these vehicles and many more with Nissan. Take it for what it is ...

I'm not sure what there is to take. Did you help? Sorta...you "helped" degrade other people who want to think outside the box for a moment and find an alternative solution to something, anything. If I genuinely believed you really wanted to help (and I don't), and if you genuinely thought the OP might just be throwing parts at a problem (which you've advocated elsewhere, and which I did not challenge because my scenario completely validated his request), then you would have looked at the FSM and simply asked, "Dearest kennyp, how did you reach the conclusion that your EVAP canister needs replacement and not the EVAP purge valve?" Then...maybe THEN...you could suggest he inspect the valve before considering replacing the canister. Now, that would have been helpful.

Instead, here we are, having a pissing contest about vehicle counts, one-off experiences, and Nissans. Well in that case, I'm on my 3rd Nissan in 20 years, and have worked numerous other Nissans and Infinitis (and a Jeep, and a WRX, and a few Kia/Hyundai). Hell, I just installed a $1600 lift kit on a 2012 Frontier last weekend for a neighbor I met the night before, rebuilt some LSDs for a 2000 Frontier last month, and just began restoring my very first Nissan, a 1998 Frontier that I bought new that year (which I started with by fixing a P1444 code that would prevent me from re-registering it...I can tell you again how I solved that problem, if you'd like). I even drove a brand new Infiniti QX60 the other week for work, which must make me an expert on QX60s now (my unsolicited opinion is that it's an annoying vehicle). Ever swapped an RB20DET into a 240SX and converted it to a 5MT, or figure how to put a rear mechanical locker into an R50 when one doesn't even exist for it, or confirm that you can do a rear disc swap on an R50 with OEM parts? Well, that's the sort of one-off tasks I solve. Does it matter for an emissions issue? No. Does it mean I can't solve an emissions problem? Certainly not.

We each bring our own experience and experiences. And, AFAIK, I have supported a few other comments from you on other topics. But, here, I do not believe to any extent that you have contributed to answering the original question, nor have you offered to help in any way. Your posts have, so far, come off as saying:

a) the OP doesn't understand the problem
b) I've wasted my time and money answering his question (yet totally solving my problem and saving money, amazingly)
c) we're shortcutting a repair process because that's not how you'd do it
d) Zimmermann makes quality aftermarket brake parts (yet frankly, I've never even heard of them).

I've said it before, and oddly only here on NICO...but if you don't have an answer, you don't have to answer.

really nasty way to deal with someone that you don't agree with.

You may construe my posts any way you'd like. I could tell you exactly how to construe it, and you would still misconstrue it. But if I come off nasty, it's because you've provoked something nasty. Re-read your own subtle responses. I take offense when someone who hasn't demonstrated that he even understands the problem and clearly hasn't contributed to the conversation effectively tells me that my time and work is cheap and wasteful, simply because he doesn't agree with the way I did it.

[yeldogt]

What you fail to understand -- even if the tank tossed out some junk -- the problem was the valve. Fix the valve and filter the canister -- end of problem. Fueler gets it ... we both get it .. you don't. I was trying to help.

I don't need to get into a pissing match with you ... but I did need to point out that you were being rude.

Best of luck.

[Kennyp]

Wow... I really got the troops riled up...

1st let me say im very grateful that hawairish took the time to detail his thoughts. To clarify I have Tried tapping it to clear it... I have a filter inline which keeps refilling so ai have tried the Cheap fix snd my next step was to clear the lines a nd replace the Cannister.... My hope in the post was to find someone who like me doesn't have OEM money to throw at a 18yr old truck everytime it pukes or Belches... Which has gotten to be fairly often as time goes on... So. Thank you for your replies but I will not be puting anything OEM that I can replace with a functional alternative.


Im just gonna leave it at that as I can see all sides here . also not feeling that great and don't wanna get into a war of the words and opinions...


Thanks Hawa for the Great deal of Pics and suggestions... You sir have been an amazing help!!

[fueler]

I am enjoying this thread

To clarify I have Tried tapping it to clear it... I have a filter inline which keeps refilling so ai have tried the Cheap fix snd my next step was to clear the lines a nd replace the Cannister....:

Tapping wasn't enough for me... man I spent hours tapping and cleaning that valve. Then, the internet pointed me toward the evap lines, which was a huge waste of time. They were clear and open.

I was ready to go buy a new valve, when I took the old valve and started hitting it really hard... I heard something inside break free, now the valve clicks when shaken, reinstalled and haven't seen the code ever since. Give that a try before you buy a canister.

[Hawairish]

What you fail to understand is that "some junk" was enough charcoal to fill about 15' of lines (roughly 1 cup's worth) and cause the valve to fail. The valve never actually failed, it just couldn't do what it was supposed to because of an outside influence. It was the canister that failed.

As an analogy, slam your hand in your door. Is the door faulty because the door won't close completely, or because your hand is in it? How do you solve the problem? Replace the door, or just move your now-faulty hand?

I fully understood fueler's suggestion. Except he also appeared to describe this process for the vent valve on the canister, which is what would likely trigger a P1446, not the purge valve for P1444. Regardless, I tried tapping the purge valve (even before it was suggested), and it was not sufficient. It is not a bad suggestion by any means for either valve. But to be clear, since you're not connecting the dots, we're actually talking about different parts.

Yes, I was being rude...warranted by your unhelpfulness, yet insistence on being helpful, combined with your passive aggressive, undermining tones and unsolicited opinions. I don't have to accept your opinions, and you don't have to make people feel like they don't know what they're doing just because they're doing it differently than you and because you haven't researched the problem.

So, in the interest of summing this up and putting a fork in it.

1) For P1444, follow the FSM. It instructs you to do some basic continuity tests on the purge valve. If that fails, remove and inspect the valve. If it has charcoal particles in it, attempt to clear the valve. It can be disassembled and cleaned out, if you are so inclined. If you have charcoal particles in the line between it and the service port 3" away, the evap canister has likely failed and needs to be replaced.

2) If you have a 98 Pathfinder are are willing and able to make some minor routing modifications to the purge, fuel, and vent lines, and possibly reroute the wiring harness for the vent valve, a 98 Maxima EVAP canister might work for you because it's a near-mirror-image of the part. It is considerably cheaper, too. I was able to make it work for a 98 Frontier which uses the same 98 Pathfinder canister. You should consider replacing hoses, and may have to fabricate a spacer and/or use longer bolts.

3) Don't just throw parts at a problem without due diligence, troubleshooting, and research. It can be costly, and may not solve the problem. Evaluate your own risks, know your own limitations.