[Z28GTOSSMike]

So my 2019 has been randomly throwing a P015d which from what I have found has to do with bank 1 sensor 1 O2 sensor. My question is which one is it? Pretty sure it is the upstream one but uncertain on which side.

[Kerry]

I think that would be front driver side. Fuel trims should be wonkey or if headers an air leak maybe?

[Z28GTOSSMike]

Originally Posted by Kerry

I think that would be front driver side. Fuel trims should be wonkey or if headers an air leak maybe?

Thanks for the reply. No headers so will probably just change out the O2 sensor if it keeps coming back. The car has been running fine but has popped that trouble code twice now about 2 months apart. The description I read about the code said the sensor is slow to respond.

[LT1_William]

Hey man, sensor 1 means upstream and sensor 2 means downstream, and I believe bank 1 is the passenger side.

But I recently had a similar issue on a 32k car, except it was my downstream sensor. By the time the 02 sensor came in the mail, the car had "fixed" itself so I never replaced the part (possible mistake). Fast forward a few months and both my cats throw codes with the car running super rich. Being forced to replace cats I instead opted for long tube headers.

[easttxss]

Originally Posted by LT1_William

Hey man, sensor 1 means upstream and sensor 2 means downstream, and I believe bank 1 is the passenger side.

Nope, bank 1 is drivers side