Sooo long story short.. Cel came on, brought to Nissan, said air fuel ratio sensor is bad, so they replaced the 02 there, but said it was stuck, and needed to replace the whole manifold. Soo I leave, and 30 miles later light comes back on.. I called Nissan and repair manager said he has no idea why it would do that.. What should I do? I have 1500 miles left on warranty so I need to get this fixed asap. What could cause this and what could I do to fix?

 

Bumppppp

 

leave it with them until they fix it ur under warrenty.

 

Don't suggest anything to nissan. They will be bias and look over other things. My o2 sensors are bad on my manifold, the reason why they keep going bad for me is cause they keep getting junked up and burned up. My car is running rich from a tune from AAM. Tell them you want the problem fixed with no issues afterward before the warranty is up.

 

do you have test pipes or anything?

 

What code is being thrown? Sounds like the same issue I have. Dealership hasn't been able to figure it out yet.

 

COMPLETELY stock. What have the dealership done for u?

 

Take it back and have them do it right.

 

cats might be bad. the same thing happend to me like no more than a month ago went throught nissans b/s bought O2 sensor and a new mass air sensor come to find out at the end of all of it my cats were bad.

 

P2a03 a/f sensor 1 b2 is the code

 

What code were you getting? Was it rich or lean?
I have similair issue dealership said replace your O2 sensor i replaced the O2 sensor and cleaned the MAF sensor but CEL light came back on 20 miles later i got code P1273
I guess it could be the cats ? or exhaust leak ?

 

Is this the Consul II/Nissan Propritery code? Looks weird. Maybe you can tell us the OBD code, generally look like Pxxxx, i.e P1283, P0203...

 

I got the P1283 after changing to High Flow Cats. I'm guessing it has something to do with the amount of air the system is now able to move with all the mods stacked up. Could also be fuel related, the code means mixture is lean (too much air, too little fuel or a combo of both). I was thinking of replacing the fuel pump and filter just in-case there a restriction there. I read on a post somewhere to check the fuel pressure and it should give you an idea of what's wrong.

 

I also got the code after changing to a a short ram intake to much air creating a lean ratio but fuel pressure could be it. i ran 6 bottle of fuel injector cleaner through to make sure not the injectors but since the z has no fuel filter could be that or the pump but i would guess that would set off the sensor on both banks not just one!
Have you been able to resolve your issue?

 

Not yet, for me the code is intermitten, once every 300-600 miles and the freeze frame data always shows it popping up at the same point in the powerband (2500-3500 rpms). This led me to believe the system is just a little bit off where one sensor is picking up a small difference that triggers the threshold. I haven't been working to resolve this code yet, but I'm always looking for additional underlying causes.

One of the guys at Techsquare thought it might be due to the 5/16th spacer. He seemed pretty sure of it so I'm a little cautious of making changes until I narrow it down. As well, after a dyno run it showed the AFR to be close to in line with what the factory sets so I'm not terribly worried about. But I did think it was a little lean on the bottom because it didn't clear out of the 14's until 5500 rpms.

 

on top of that I would get the service manager to write a written agreement that this issue was brought up prior to warranty expiring and that you want the warranty work honored on this particular problem until it is resolved. this should allow you to keep driving it if they are f'ing around and not fixing it correctly.

 

My sensors and cats went bad a year ago on my '07 Z. Nissan said it was caused by my K&N drop-in filters. They replaced all of it under warranty and put OEM filters in. They thought the oil from the filters plugged the sensors. Thing is the filters only had factory oil on them. I've since changed to a Nismo intake with no problems.

 

+1, After everything is said and done make sure you a$$ is covered. Don't let them BS you around until its out of warranty and then you have to live with it. As is, that will have problems passing a smog test due to the CEL, you can let that go.

 

Those guys are noobs. Any good mechanic can diagnose a problem, especially with the MIL on. Take it back and have them fix it, done deal.

 

BTW, they're supposed to run the monitors and make sure the MIL doesn't come back on.