NEED HELP!! Car is Broken!

[gwoods]

I had a similar issue to this with my focus SVT...turned out it was just a clogged fuel filter....

May want to check that...most modern cars have them and people don't really realize they should be changed every 20k or so...

ME TOO 1991 Sunbird I bought for $100 with a blown head gasket.

Did exactly what Kenricks car is doing + would NOT shift under full throttle, if you let up it would shift.

Pontiac dealership didn't charge me and told me to replace the ff.

[Kenrik]

I liked the idea that it was the O2 sensor... I don't care to track down another issue..

The fuel filters are only in the tank on the G and from what I have read get replaced when you do a fuel pump. I personally thought it was the O2 sensors because they are due to be changed at 100k and I have test pipes.

My Exhaust smells like a 1982 Ford Econoline Van...

when I drove it yesterday it was not bucking but I could feel it had less power then it usually does.

Are the four O2 sensors different?? I have seen Universals for $33 each.. http://www2.partstrain.com/sto...+5843

Do I buy 4 of those? are the upper O2s different from the lowers??

Which ones do I get? I need the cheapest possible that will work.

[SVTCOBRA]

I have also read that it's good to replay ALL 4 after your car has so much mileage....IF you are planning on keeping it.I would have done all 4 of mine in the cobra if I were going to keep it.Doesn't answer your question, but was just adding my 2cents.

[SteveTheTech]

It sounds like your ECM is in fail safe mode. Was your CEL on before? It sounds like you may be having a problem with you throttle motor or MAF. Those are the symptoms on a stock vehicle, it sounds more likely your H02Ss may be burned but that may not be your only issue. Fuel strainers very rarely get clogged. I would have to see some engine parameters to be able to point you in a better directions.

[gwoods]

I liked the idea that it was the O2 sensor... I don't care to track down another issue..

The fuel filters are only in the tank on the G and from what I have read get replaced when you do a fuel pump. I personally thought it was the O2 sensors because they are due to be changed at 100k and I have test pipes.

My Exhaust smells like a 1982 Ford Econoline Van...

when I drove it yesterday it was not bucking but I could feel it had less power then it usually does.

Are the four O2 sensors different?? I have seen Universals for $33 each.. http://www2.partstrain.com/sto...+5843

Do I buy 4 of those? are the upper O2s different from the lowers??

Which ones do I get? I need the cheapest possible that will work.

Pre cat and post cat will be different, right to left the same. So you need 2 pre cat and 2 post cat.

WOW those are exspensive!

I bet the only difference between the universal and the Infiniti specific is the connector on the end BUT you could always cut your connector off the old sensor and splice it onto the new sensor.

Good LUCK!

[C-Kwik]

It sounds like your ECM is in fail safe mode. Was your CEL on before? It sounds like you may be having a problem with you throttle motor or MAF. Those are the symptoms on a stock vehicle, it sounds more likely your H02Ss may be burned but that may not be your only issue. Fuel strainers very rarely get clogged. I would have to see some engine parameters to be able to point you in a better directions.

I don't think it would go into a failsafe over bad O2 sensors. And if something else were to cause a failsafe, a code would likely come up. My thought is that its likely something else that is causing the poor running condition (that is not out of the range enough to trigger a code) and may be causing an O2 sensor reading that is out of range. I would go through the entire diagnostic procedure for the given codes in the FSM. Otherwise you may end up replacing the sensors and still have the problem. Or worse yet, if the problem caused damage to teh O2 sensors, an unresolved problem may destroy your brand new sensors as well.

[tollboothwilley]

This is debatable. One of our lovely newer members made it a point to "inform" us that there are no pre-cats on our cars. Then made sure we all knew how stupid we were.

I looked up the FSM and couldn't find much info on the Cats. There was no mention of a pre-cat that I saw.

We do have 2 oxygen sensors before the cats at least for the 2003 (they are the same sensors for both sides of the manifold) and we have 2 sensors after the cat.

I'm positive of this. The parts manual is clear on this.

http://www.infinitipartsonline...gid=0

[tollboothwilley]

The pre cat O2 sensors are unheated (2 wire) , the post cat sensors are heated (4 wire)

The pre cats (front 2) are the same, where as the post cats are different right to left.

You should be buying 2 universal unheated O2 sensors, and i believe 2 heated O2 sensors(even though they are different from the plug and play stock options). It will just be a little splicing of wires, which sometimes sucks a nut when you dont have a lot of room.

[Sentientbydesign]

We do have 2 oxygen sensors before the cats at least for the 2003 (they are the same sensors for both sides of the manifold) and we have 2 sensors after the cat.

I'm positive of this. The parts manual is clear on this.

http://www.infinitipartsonline...gid=0

Ok, here's the issue. I think I misunderstood the original post.

It makes sense that there are two O2 sensors before the cat (pre cat) and two after.

I thought Kenrik though there were two sensor in/on the "Pre-cat" - essentially a cat before the main cat that prevented emissions while the exhaust was still cool. I think Nissan has/is doing away with them due to all of the Sentra/Altima engine failures that were caused by the "Pre-cat".

[SteveTheTech]

I don't think it would go into a failsafe over bad O2 sensors. And if something else were to cause a failsafe, a code would likely come up. My thought is that its likely something else that is causing the poor running condition (that is not out of the range enough to trigger a code) and may be causing an O2 sensor reading that is out of range. I would go through the entire diagnostic procedure for the given codes in the FSM. Otherwise you may end up replacing the sensors and still have the problem. Or worse yet, if the problem caused damage to teh O2 sensors, an unresolved problem may destroy your brand new sensors as well.

Your right there are only a few DTCs that will cause the ECM to go into fail safe and they are all related to the electronic engine control, ie. TPS or throttle control motor failure, APP sensor either 1 or 2 failure, something like that I think I may have not have re read well enough what I was writing. The ECM really only goes into fail safe when it cannot rationally control ECM outputs based on incorrect input signals or an open circuit. This problem most likely had a corresponding diagnostic trouble code and may have been erased earlier.Most likely pertaining to an input sensor issue.I don't know off hand every DTC but I would not be surprised if those were either slow monitoring code or MAX voltage codes. These codes are not uncommon with an ECM that is designed to have cats on it detecting a voltage sweep in the H02S2s due to a lack of catalysts (damn federal emissions laws), the light may even have been flashing. Without seeing what calculated load and grams per second are I would be very hesitant to recommend a repair for this incident.

[Kenrik]

It never went into "safe mode" I could, and still can rev the car all the way to the redline. it's just that it bogs down at times. After about 3.5k - 4k it would buck and kick into feeling normal again. I think after that point the fuel map was correct and it smoothed out.

I drove it the day that I tested it and it was not bogging at all but it did feel like it had less power then it usually does.

I have not been driving it since Monday because I need to wait for my next paycheck to get parts.

What I need to know is this > if I do the O2 Sensors, you guys have said that the after cat sensors are different left to right?? If so how can I use universals if they don't specify left or right?

I need to know that the sensors I'm buying are 100% correct. Can someone help me by pointing out exactly where I can get them for the least amount of $$

I'm looking to do the post-cat sensors first.

I doubt it's the MAF but I can clean it, the plugs only have 10k miles on them so they should be good.

[SteveTheTech]

Ahh I see what your talking about now it sounded like something different. The upstream sensors are called Air/Fuel Ratio sensor and they do in fact work very differently work differently from conventional O2 sensors. They cycle in the millivolt range and replacing them with conventional universal sensors will make everything worse. Your short term fuel trim is off I would not be surprised if it was not leaned out, it may be to the extent of causing a lean miss. I am thinking your ALPHA reading would be in the ~70s, when statiometric is 100%. Do you have any fuel modifications?

[Kenrik]

No fuel mods.

I have a Spacer, Z-Tube & Test pipes.

[Kenrik]

I found the problem!!!

it seems my car is slammed too low

I went over a nasty speedbump and the O2 Sensor made contact damaging the wires and bending the metal. The day the car had all of the issues it was raining which caused it to short out and run like crap!

That's why when I drove it later, and also today it felt fine, a bit slow but ok. it's because it was dry/not shorted.

I replaced it with a Universal Bosch.. the wires all match up same colors and everything.

Car runs like normal again, I sensed a little hesitation at one point but it may be that the computer was still a bit confused.

I cleared the codes and the CEL went off.

I plan to replace all four O2 sensors with OEM'S within the next 10k miles. Until then this is a good $60 Band-Aid.

Carry on Chaps!

[SteveTheTech]

Congrats on the fix , that's pretty wild if the wires were shorting to each other they would be showing an extremely rich running condition, and all of your problems. My wife did the same thing once with her Acura, she hit a large piece of plastic on the Beltway, and the battery light came on. Those idiots actually wired the 02 sensor wires to the alternator circuit. That one kick my a** for a bit.

[gwoods]

Have you checked under the hood for loose wires?

[Kenrik]

Ehhh CEL came back on. it's running a lot better but sometimes it bogs a bit.

I think it's due to using the universal & my sucky soldering skills. I'm still going to get the OEM'S when I'm able.

[Jacko3]

Kenrik:

Well dlone in finding the problem. Don't worry about the CEL as long as you are not constantly under WOT. Drive it gently, until you get paid. I had the same issue once with CEL On, and the car drove great without problems. The g is a remarkable car--can keep going even when sick or malfunctioning.

[Kenrik]

Ehh... Most of the time it works fine but it still is acting up.

I need some help from you guys!

I can't seem to find the correct O2 sensors for a decent price. Some places list that there is a difference between the left and right O2 sensors and others do not. Some only sell one side.

I still don't know about the uppers? are they more important then the lowers?

HELP!!

I need to find a place to buy OEMs for around $100 each (less if possible) I can't afford to pay $600 for four new Sensors!

Is there anyone here that works at an infiniti dealership that can help me? I need to track down OEMs for a decent price ASAP.

[SteveTheTech]

There is a definite difference between the downstream O2 sensors the connector between bank 2 (drivers side) is green and bank 1 (passenger side) is blue. The up streams are Bosch Air/Fuel ratio sensors, (I would be skeptical of finding these cheap as they have a very short sweeping range). I would recommend waiting a little bit and save up and buy the right parts Air/Fuel sensors and HO2 sensors are basically useless if they have been dropped from a height of <6".

[Sentientbydesign]

EverythingG35 and Riverside Infiniti (Tony-Tell him I sent you).

Those are the only places I can think of.