at88mph

I know its a rear O2 I need to replace, and I believe it stated being the right side, but since the 02's in the rear swap sides,(ie the one hooked up on the passenger side harness goes into the drivers side pipe, and the one hooked up on the drivers side harness goes to the passenger side pipe) so which one do I want to replace for this code? The one going to the drivers side harness or the passenger side harness?


Thanks for any help

FRCTony

This is indicating a heater circuit failure I believe.

Should be drivers side rear.

Make sure to check wiring carefully first.

at88mph

Just to make sure I'm understanding correctly, you mean replace the one that connects to the drivers side harness and the 02 itself is in the passenger side pipe; correct?

FRCTony

Doesn't matter what harness it's connected to... The one indicated by the code should be on the drivers side behind the cat.

at88mph

See, that's where I'm confused....the way they're hooked up (on my car) is one o2 plugs into the harness on the drivers side and then screws into the passenger side pipe after the cat and the other o2 plugs into the harness on the passenger side and then screws into the drivers side pipe after the cat...so which one do ya replace?

jirasvet

I understand where you are getting confused. That is just the c-5 design that the rear O2 sensors wiring harnesses cross to opposite sides.
The driver side(bank 1 sensor 2) O2 connecting at the passenger side and the passenger side (bank 2 sensor 2) O2 connecting on the driver side.
Even though the driver side rear O2 sensor wiring harness connects to the passenger side,the PCM knows to read it as bank 1 sensor 2. That
is just how GM decided to run the connectors and wiring harness.
Like stated the O2 sensor you are looking to replace is on the driver side rear.
I hope I did not confuse you anymore

at88mph

Gotcha...so I wana replace the one that connects to the passenger side harness but goes to the drivers side pipe, correct?

jirasvet

yes

at88mph

Thanks! Replaced it last night and drove it around all last night and today without the 'Check Engine' light coming on!