Hello, all my SES light is on yet again well, it has been determined it is an 02 Now, when i had it scanned at autozone they said it was bank 2 sensor 2. I asked the kid if he knew which one it was and he didnt know. I figured that bank 2 is opposite of cylinder #1 so it has to be passenger side, but would #2 be the sensor after the cat?

 

You are correct, bank 2 sensor 2 is the passenger side post cat.

 

BINGO!

 

I had a P0161 code, or something like that - it was a 2fer code saying the back O2 was reading wrong, and the pasenger air pump check valve was bad.

I replaced the check valve - roughly $ 15.00 - and that was all she wrote.



Might be worth a look.


Britt

 

Well, my car has 77k miles on it so its about that time for the sensor to go plus the old cat was hollowed out so i am sure it cooked it even faster.

Now, once i replace the sensor can i just disconnect the positive battery terminal for about 15 mins and will that clear the code? I did it to my jeep when i was replaceing its 02 sensors and it cleared the codes, i am just currious if it will work on the maro? Thanks

 

Yes, you can disconnect the battery.

Or:

Turn key on, don't start car
Pull PCM BATT and PCM IGN fuses in engine compartment
Wait 5-10 minutes
Turn ignition off
Replace fuses

 

I had the same problem and replaced the passenger rear O2 sensor twice. Turns out it was the Driver's side CAT that was bad... I took it to the dealership and they replaced it. I know CATs are covered for 80k miles under federal warranty, I dont recall how many years, but the dealership will charge you something like 80 bucks for the scan if it turns out to be part not covered under the federal warranty. For me, it was a CAT and cost me nothing.

 

Should be able to just pull your pcm fuse without ignition on. That way you wont lose your radio settings.

 

Thanks for the replys guys, i guess i will just pull the pcm fuse so my radio doesnt lock up. I replaced my drivers side cat with a (newer) cat from a 2000 trans am with 50k on it. I plan on going with LT's in the near future so i dont need my current cats for long just long enough for me to get my next tax refund until i can get a y pipe and toss on some highflows.

The PCM fuse is located on the drivers side right? Not in the interior of the car but near the fan relays etc Sorry its midnight and i just got home from work

 

Yes, the fuses you want are both under the hood. Not sure what code you have but my manual says the SES for the rear 02's will go off by itself after 3 consecutive cycles, and store it in "history" for 40 more after the problem is corrected.

 

Thanks for the help. I am still new to OBDII and i have found each car manufacturer has something a little different for each one. By cycles do you mean the turing of the key? Like if i start my car and keep it running for a duration of like 10 mins or so 3 times consecutively the PCM will adjust and then shut off the SES light?

 

I'm thinking 3 cold starts. Here's what it says for P0161 - "The PCM turns off the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail...A history DTC fails after 40 consecutive warm up cycles, if no failures are reported..."

 

Just checked and it says the same thing for the other bank2, sensor 2 codes - P0157, P0158 and P0160.

 

Hunh? Sorry you lost me...so 3 cold starts should clear it then is what your saying? How many bank 2 sensor 2 codes are there?..lol

 

If it doesn't clear on the 4th cold start I'd reset it manually. I didn't realize there were so many bank 2, sensor 2 codes either...lol

157 - circuit low voltage
158 - circuit high voltage
160 - insufficient activity
161 - heater performance