Cel p2a00
 

50 miles after I reseted my ecu due to head unit upgrade, I got this code. I already searched the forum and didn't really find a fix for it. Other forum members seemed to had an exhaust leak of some sort due to an after market set up, but I'm pretty much stock other than stillen gen3's.

So once I got home I deleted the code just incase it wouldn't pop up again. About 60 miles later the code showed up again. I jacked up the car to check the exhaust system and everything was good. Then check all vacuum lines, everything was good. Didn't check 02 sensors because this isn't the code for them so I checked my MAF sensors.

Took both MAF sensors out and cleaned them with CRC electrical cleaner and installed them. Since then I've put 200+ miles on the car with no problem. My guess is this might of fixed the problem. Hope this helps anyone else that might be fighting this code.

It is possible that the g3s are leaning out the engine which is causing faults with the O2 sensors. Did you unplug the battery when you did the intake install? Maybe when you reset the ecu it diverted to stock fuel trims.

EDIT:

This is what I found on another site

this is a *itch code. It could be an exhaust leak, intake leak, injectors, or something with your O2 or its harness.

Try the obvious:
check for cracked TP/HFC (most common)
check for exhaust leaks between cat and exhaust manifold (second most common)
check for exhaust leak between block and exhaust manifold (not very common unless you recently replaced your headers)
check for exhaust leak between cat and y pipe (will most likely trip P0420 at the same time)
check for intake leak( data log to see what your MAFs are reading)
check for faulty primary and secondary O2( easiest way is to switch the sensors and see if it trips the other side)
check for faulty MAF (data log to see what your MAFs are reading)

Crazier things to check
O2 harness (bust out the multimeter)
Injectors (have fun with this one)

When I first installed the gen3's I did disconnect the battery. They've been on for quite some time now without throwing a code. The code didn't show up until the last battery disconnect when I replaced my stereo. But after cleaning the maf sensors I've been driving it hard and for long periods of times and so far so good.

I even connected the car to my oscilloscope and everything seems to be running properly now.

My other guess is that I probably over oiled one of the K&N filters and over time threw off one of the sensors. The driver side MAF sensor was pretty dirty.

I've been having the same code for a month. Seems to come on when it's colder on every other start. I reset it when I'm at the track and it never comes on. I bought some MAF cleaner but haven't used it yet.

This is such a PITA code. Last year after doing CBE and LTH's it was fine. Then a few hundred miles later it started coming on. I'd reset it but it would always come back within 20-30 miles. Finally got Uprev and just turned the code off till I could get it tuned thinking that the car was just running a little too lean with the plan to re-enable it after the tune. Long story short after it was tuned and the code re-enabled the damn thing came back after a few hundred miles. I watched the dyno runs myself along with the AFR's so I know everything looks good. I'm turning this code back off this weekend when I get a chance.

That's what I was trying to find out exactly was if you could turn this code off.

It's in the same list as all the other DTC's that can be enabled or disabled. Just need the Uprev tuner cable or have your tuner do it for you.

You should definitely clean your MAF, we might be on to something here.

It makes sense in your situation, but my exhaust is all still stock for now so I don't understand why it came on. The only other thing I could think of is a conspiracy against my nissan dealer. After I installed my stereo I went in for the steering lock recall. Since then the CEL has shown up. So far after I cleaned the MAF's it hasn't shown up, but if it shows up again I'm blaming nissan lol

Update:

The CEL came on once again. I jacked up the car and noticed the metal mesh in the Y pipe was missing a chunk. Would that have anything to do with it?

Yes. That is creating an exhaust leak which is affecting your O2 sensors.

Just cleaned my MAF yesterday. Going to see if that helps remove my code.

I should've followed your trouble shooting list from the get go. I pretty much went to taking all parts off that had to do with intake/exhaust. Turns out the hose clamp on the ds throttle body was lose, and the intake tube moved out a bit to the point that it was sucking air from there. Thanks for all your help. The code finally went away