Yep, my CEL went off in the summer and came back once temps got near freezing.
Ilya (or anyone else really), do you still have access to your family car lift?
It might not affect emissions testing (in most jurisdictions), but it is guaranteed to affect the vehicle's emissions if you did a tailpipe test. Without the factory installed secondary catalytic converters, the vehicle is certainly releasing more pollutants than it was certified for.armybrat wrote: ↑Mon Jan 21, 2019 5:42 am
Good catch! I meant to say that the second cats are downstream of the O2 sensors. IMHO removing those wouldn't affect anything emissions wise...however, the flange with the baffle is before the sensor like you pointed out - you might be on to something there. I've never pulled any O2 codes; just the P0420. The firing order is 1-8-7-3-6-5-4-2. The exhaust pulses are not in order on the left bank, per se. The right bank fires 8-6-4-2 while the left bank fires 1-7-3-5. From your drawing it looks like the manifold tubing routing has something to do with this, and that's why they are different. Maybe the baffle helps to balance the exhaust pulses somehow. Could also have something to do with VVEL on the left bank. I found some good engine specs here:
https://www.engine-specs.net/nissan/vk56vd.html
Might be able to glean something from there.
I do have access to my dads lift still...I haven't been disowned...yet .EdBwoy wrote: ↑Mon Jan 21, 2019 10:16 pmIlya (or anyone else really), do you still have access to your family car lift?
Do you think you'd be able to inspect the manifold area, preferably during the cold season when the CEL comes on?
Please remind me, are you getting both P0420 and P0430 or only 420, bank 1?
This whole fiasco could be over a crack in the manifold, or some defect that rears its head when the outside temps affect the material in such a way.
Awesome! So far, so good. Keep up whatever you're doing to distract the family for at least the next 1,000 miles.Ilya wrote: ↑Tue Jan 22, 2019 7:16 am...
I do have access to my dads lift still...I haven't been disowned...yet .
I will be needing an oil change in another 1kmi or so, should still be cold so I'll take a look. Which side is bank 1 when looking from under the car? sorry lol.
Also, I'm only having the P0420 last I checked.
Here in NC, I don't know if they do a tailpipe test. They hook up their scanner device to the OBD2 port and perform their test of the emissions system. They run the car for a length of time and make sure it doesn't pull any codes. In addition, they do a visual inspection. The print out of the results just say pass or fail. In my case, the visible amount of soot seems to be the same with the custom exhaust vs the original exhaust. I've been wiping my exhaust tips since day 1, so if there's a difference in output it's negligible to the eye.EdBwoy wrote: ↑Mon Jan 21, 2019 11:51 pmIt might not affect emissions testing (in most jurisdictions), but it is guaranteed to affect the vehicle's emissions if you did a tailpipe test. Without the factory installed secondary catalytic converters, the vehicle is certainly releasing more pollutants than it was certified for.
Very good write up, something to think about.EdBwoy wrote: ↑Mon Jan 21, 2019 11:51 pmSo, back onto the engine layout, all of the Nissan V8s I referenced earlier used the same firing order. All of them used an exhaust manifold that was mainly log style. The M56 at least tried with the Tri-Y manifolds.
When you look at them in firing order, it makes sense...
I agree about the engineering with respect to the engine. However, I disagree about exhaust manifold design with this particular motor. The exhaust system for the VK56VD sucks, period. Manufacturing the exhaust manifold and catalytic converter as one unit and having to lift the motor to change it out is a poor design even if (hypothetically) the unit is supposed to last the "lifetime", aka 100,000 miles, of the vehicle. There is no need to have a secondary set of cats; the primary cats could've been installed in that space under the car, bolted to the same manifold flange and flanged on the exit end to the Y-pipe just like the 3.7 engine. Instead, the engine is having to force the exhaust through 2 pairs of cats and a pair or resonators that choke down to 1-3/4" diameter. No wonder the cars run rich and clog the cats, especially in the colder months, evidenced by excess soot at the tail pipes. Sorry excuse for an exhaust system IMHO.
Great pic, looks like the AWD - noticing that the passenger side secondary cat may be the offset one, maybe to clear the transfer case? I know I mentioned in my previous post that the driver's side cat was the one that was offset...hard to tell though.EdBwoy wrote: ↑Tue Jan 22, 2019 8:56 amBank 1 is the left side of the engine. That is the driver side for the US models. From under the car, it's going to be the one closest to the steering shaft. I'd send you a picture, but... jackstand crew here. Lol
You might as well check both manifolds though.
Edit: from a picture you posted elsewhere in the forum, I have highlighted bank 1 for the V8. It is the opposite for the V6
Might be negligible to the human eye, but not to the atmosphere.armybrat wrote: ↑Sat Jan 26, 2019 9:03 amHere in NC, I don't know if they do a tailpipe test. They hook up their scanner device to the OBD2 port and perform their test of the emissions system. They run the car for a length of time and make sure it doesn't pull any codes. In addition, they do a visual inspection. The print out of the results just say pass or fail. In my case, the visible amount of soot seems to be the same with the custom exhaust vs the original exhaust. I've been wiping my exhaust tips since day 1, so if there's a difference in output it's negligible to the eye.
As a DIYer, I 100% agree with you that the design sucks for at home repairs. But we have to agree to disagree on the other aspects.armybrat wrote: ↑Sat Jan 26, 2019 9:03 amI agree about the engineering with respect to the engine. However, I disagree about exhaust manifold design with this particular motor. The exhaust system for the VK56VD sucks, period. Manufacturing the exhaust manifold and catalytic converter as one unit and having to lift the motor to change it out is a poor design even if (hypothetically) the unit is supposed to last the "lifetime", aka 100,000 miles, of the vehicle. There is no need to have a secondary set of cats; the primary cats could've been installed in that space under the car, bolted to the same manifold flange and flanged on the exit end to the Y-pipe just like the 3.7 engine. Instead, the engine is having to force the exhaust through 2 pairs of cats and a pair or resonators that choke down to 1-3/4" diameter. No wonder the cars run rich and clog the cats, especially in the colder months, evidenced by excess soot at the tail pipes. Sorry excuse for an exhaust system IMHO.
I was pleased to see this posted on an enthusiast forum, as a bonafide geezer it gives me hope for the future of DYI "hot-rodding":
Point taken. Soot is a visible signature only...however, the EPA sets the standard for the Clean Air Act, the states voluntarily enforce those standards in exchange for funding, the EPA is left to enforce it in those states that choose not to participate. Also within the states who do enforce the standards, there are counties who choose to let certain provisions slide for older vehicles. For example, here in NC, vehicles 25 years and older are exempt from emissions inspections. As long as my car doesn't throw any codes and passes the state emissions test then I am still in compliance regardless of less cleaning from removing the secondary cats.EdBwoy wrote: ↑Sat Jan 26, 2019 1:43 pmMight be negligible to the human eye, but not to the atmosphere.
Most places do not do tailpipe tests, that's why I said a modified car would still pass emissions in most places. My point was that the manufacturer determined that the vehicle needed 2 sets of "air cleaners" and that removing one set was undoubtedly going to result in less air cleaning when parked side by side to a stock car, whether we can see/smell the difference or not.
Maybe a little more clarification - I was not talking about gutting the primary cats. The secondary cats are not designed to function as primary cats, plus they are too far away from the manifold to function properly anyway. I was talking about redesigning the exhaust manifold altogether, making it longer similar to headers, and bolting the primary cat directly to it, similar to the 3.7 motor. The AF and O2 sensors would have to be relocated to maximize proper function, and retuned of course to comply with emissions testing.EdBwoy wrote: ↑Sat Jan 26, 2019 1:43 pmI don't fully understand the difference/allowance in the secondary cats that are unmonitored, but I know of someone who did more or less what you proposed. Gutted the primary cats and put the downstream o2 sensor after the secondary cats, thus using the secondary cats as primaries. There are no codes but the car stinks. Which to me means that for CEL purposes, the secondary and primary cats clean just as efficient as the other. I also infer that having 2 sets is important for thorough cleanup beyond being marginally legal.
True...however, the VK56VD has only been around since 2010, so there was no reason to complain. Now a lot of these motors are reaching, or have reached, the so called "lifetime" threshold, and we are beginning to see (IMHO) a design flaw in the exhaust manifold system, and heck yeah, folks are complaining, and not just the DIY'ers. Most folks didn't know that the exhaust manifold was an integrated assembly, and also were not aware of the complexity and cost of having it replaced. It's not just here and there; it seems to be a universal issue among the 5.6 owners, stock or modified.EdBwoy wrote: ↑Sat Jan 26, 2019 1:43 pmAs a DIYer, I 100% agree with you that the design sucks for at home repairs. But we have to agree to disagree on the other aspects.
For one, nobody ever complains about the design/engineering of components unless we need to do a repair and can't quickly access it.
Secondly, I can't authoritatively say a manufacturer did not need to have secondary cats. Catalytic converters are expensive and the manufacturer isn't throwing you a single penny they don't have to.
When an engine is designed, they go for the main 3 principles of a production engine - (emission, output/power, and fuel economy). If an engine fails and cannot be reasonably improved, then out it goes and it never sees the light of day. Then other components are designed around the engine. The manufacturer tells an exhaust company what they expect the car to do and the exhaust company will design the exhaust system (sometimes from engine to tailpipe, sometimes just a section).
So, the exhaust is designed by a company that does exhaust systems all day and presumably understands what emissions regulations to follow. For Nissan, we are talking about Calsonic Kansei and Sango (Sango for the V8, is my guess). These guys then work around size, weight, packaging, sound levels, performance etc... and COST.
I believe that if the 5.6 direct injection injection engine could share infrastructure with the 3.7 port injected engine, then they would. In fact, that would make it cheaper for Nissan to produce similar templates, and just flange the catalysts. It's just they can't do that and stay legal and/or within budget. No official word from Nissan, this is my opinion as a design engineer.
Just out of curiosity I looked up a few integrated exhaust manifolds. There are several as you mentioned in the 4 and 6 cylinder configuration. Not really that many in the V8 and V10; only examples I was able to find are the Lexus LS460, the Cadillac 4.6L, the BMW X5 and M5 E60 and S85 motors. I really didn't look much; I'm sure there may be a few others, but from what I found, there are a lot more that use bolt on cats, especially performance models...no reason why our cars can't do the same thing.EdBwoy wrote: ↑Sat Jan 26, 2019 1:43 pm...A lot of manufacturers of high output V8s and V10s utilize the same design...You and I are free to install 3" true dual exhausts and delete the cats once we get the car, but in reality we are affecting an aspect of that engine triangle. Whether we give a crap about power, fuel economy or emissions then is a matter of personal opinion, but it is a scientific fact that most of the "mods" we do before the muffler with good intention end up tipping the scale unfavourably for intended design.
I typically do not engage when I see posts of people opening up the power by enlarging the "restrictive small diameter" OEM exhaust/intake. I understand there is more to it.
Here are some sample screenshots from one such exhaust designer:
Again, we can choose to agree to disagree on the engineering and design. I agree that they are a pain for you and I to replace at home, and expensive to pay someone to do.
Hopefully soon, with enough digging, we can find what the problem is.
Gotcha now. Pardon my misunderstanding.Maybe a little more clarification - I was not talking about gutting the primary cats. The secondary cats are not designed to function as primary cats, plus they are too far away from the manifold to function properly anyway. I was talking about redesigning the exhaust manifold altogether...
I don't know how to appropriately respond to the highlighted area. Nissan has been doing it in the States since the 90s. I understand that not everyone pops the hood of a car and looks underneath before they buy it... in fact people close to me have told me it's very strange that I do that, but I usually look up and down to anticipate what kind of repair and maintenance is possible with the engine in place....folks are complaining, and not just the DIY'ers. Most folks didn't know that the exhaust manifold was an integrated assembly, and also were not aware of the complexity and cost of having it replaced. It's not just here and there; it seems to be a universal issue among the 5.6 owners, stock or modified.
I honestly don't know what fraction of V8 and V10 manufacturers use the integrated manifold versus a flanged cat, but I do know that more than our vehicles do, which means it's not just a Nissan quirk. I didn't look too deep either, but I was going off memory of the cars I'd owned and viewed with intent to purchase. I also researched lightly a few years ago when replacing manifolds on an M45. (I'll explain more at the bottom). I had seen the Lexus LS430 and it had a flanged cat, didn't know they went integrated on the LS460.... There are several as you mentioned in the 4 and 6 cylinder configuration. Not really that many in the V8 and V10; only examples I was able to find are the Lexus LS460, the Cadillac 4.6L, the BMW X5 and M5 E60 and S85 motors. I really didn't look much; I'm sure there may be a few others, but from what I found, there are a lot more that use bolt on cats, especially performance models...no reason why our cars can't do the same thing.
Yep, that's me who keeps mentioning it. That 03 M45 I bought had a P0420 catalyst code. Efficiency below threshold, etc. It had been misdiagnosed as a clogged cat which was then gutted. When through a series of unfortunate events, I got to an engine replacement, I realized the manifold was cracked. Looking online, I started seeing more complaints from Nissan V8 owners with that type of manifold.Something was mentioned about cracked manifolds; I am not aware of any issues with cracking; only the threshold efficiency issue
Sorry I had missed your post Sir; and thank you. I suppose I'm an old soul as well. I am not anti-modifying things.
Oh yeah you'd be surprised at how many folks don't really know the intricacies of their vehicles. Some don't even know their engine size LOL. A lot of M56 owners didn't know about the oil consumption, and I am willing to bet that the engine failures that folks have been experiencing can probably be attributed to not checking the dipstick and adding oil in between scheduled maintenance.EdBwoy wrote: ↑Sun Jan 27, 2019 1:48 pm
I don't know how to appropriately respond to the highlighted area. Nissan has been doing it in the States since the 90s. I understand that not everyone pops the hood of a car and looks underneath before they buy it......folks are complaining, and not just the DIY'ers. Most folks didn't know that the exhaust manifold was an integrated assembly, and also were not aware of the complexity and cost of having it replaced. It's not just here and there; it seems to be a universal issue among the 5.6 owners, stock or modified.
Something was mentioned about cracked manifolds; I am not aware of any issues with cracking; only the threshold efficiency issue
The newer M's also employ flex piping. I believe those are instrumental in minimizing vibration which can cause manifold cracking plus help with cabin noise. When I installed my custom exhaust, I added flex connectors to mimic factory specs. I will keep a lookout though.EdBwoy wrote: ↑Sun Jan 27, 2019 1:48 pmYep, that's me who keeps mentioning it. That 03 M45 I bought had a P0420 catalyst code. Efficiency below threshold, etc. It had been misdiagnosed as a clogged cat which was then gutted. When through a series of unfortunate events, I got to an engine replacement, I realized the manifold was cracked. Looking online, I started seeing more complaints from Nissan V8 owners with that type of manifold.
I know I looked at a number of VK56DE issues with the code and cracked manifolds.
Consider that the 06+ M45 with the same integrated manifold had similar oil consumption habits, but zero of the p0420 and cracked manifold issues of the prior years. It employed a flex pipe though.
Yes sir - so far, no CEL!
Agreed! Aston Martin provides some very good numbers. They guarantee it for around 60,000 miles. As a reference, the most popular supercars offer 3 year/unlimited mile warranties as standard. Hehehe, what a catch to be in!
And then there's maintenance. Race car motors are, with few exceptions, built to last for the duration of a race. Even millionaires wouldn't buy a car that needs an engine rebuild every 500 miles. Which means the components that go into spinning the Valkyrie V-12 had to be exotic enough to withstand four-figure power at five-figure revs, but not so new and exotic that engineers couldn't be sure they'd last for decades. Cosworth stuck to known materials, and aside from some carbon-fiber structural components, it was made with relatively conventional steel and aluminum alloys.
Well, that's pretty impressive on paper, and if I could afford buying and fuelling one, the unlimited mileage warranties of supercars make them excellent daily drivers. I don't know if they account that a sizeable chunk of a supercar's life these days is spent doing cold starts and promptly revving its heart out for YouTube exhaust videos... So the real world longevity is yet to be determined.Wood claims that Cosworth shied away from using the latest sci-fi materials whose reliability wasn’t wholly known, preferring to use the best of established stuff. So there’s aerospace quality alloy heads, and titanium rods and valves, but it’s all proven tech. And while the engine lifespan isn’t going to worry a small-block Chevy, Aston’s V12 will last at least double the 31,000 miles AMG says it’s motor will need between rebuilds. Maybe more, according to CEO Andy Palmer:
"Our expectation is that by 100,000km (62,000 miles) it won’t have blown up, but some of the components will be worn out," says Wood, before adding: "not that many owners will ever get anywhere near that figure."
But Cosworth subjected the engine to over 200 hours of dyno testing (‘much of it at full throttle’) to make sure they would last the course without needing a tear-down after every third Sunday drive. The service requirements are relatively modest give the spec, comprising an oil change every 3-4000 miles.
I just wanted to update my ongoing P0420 issue...the CEL came on again at 99,000k, and it went out on its own after about 150 miles or so, for the third time. For the second time, it stayed out. The first time it stayed out, I went ahead and added a bottle of Cataclean anyway. This time, I decided to not add any. I reset the DTC, and I'm at 100,100k and still going strong.
I would go back to the premium ethanol gas. I believe the ethanol free gas is not good for the three way catalytic converters that are in our cars. Save that gas for lawn equipment or for older cars with two way cats or no cats at all. Using motor oils with higher levels of ZDDP, like high mileage motor oils can also hurt your cats as well.
I wouldn't worry about it. As long as the octane rating is above 91 on the pump, it's fine. LINK
I apologize if I misguided you on that matter. I do not think there is anything wrong with the firing order that Nissan has used since at least 1989. I think the issue is structural - probably a crack in the manifold, or even a faulty catalyst element; none of which we can confirm without a visual observation. However, the ethanol vs. non-ethanol experiment might help shed some light.
I harbor no ill will against my Northern friends, but I sure hope that the temperatures drop back down for you guys for the sake of our experiments . We are already into the 50-60*F range over here. St. Louis Metro area.tlaspec wrote: ↑Wed Mar 13, 2019 1:38 pm...I will take a video to share if the temps drop again but the noise is very similar to piston slap videos on youtube.
Does anyone else with the P0420/30 code notice any excessive knocking sound from the engine during first 5 minutes of cold start? Once i knew what to listen for the noise can be clearly heard from inside the cabin...