JimMueller

iTrader: (9)

I went to the dealer today intending on buying replacement front O2's. They told me the Bank 2 sensors were both the same (F&R), and the Bank 1 sensors were the same (F&R), but that the part numbers for each side were different.

I thought we used the same part number for the front O2's, and a different part number for the rears? The rear's are disabled, and I'm just looking for the appropriate O2's for the pre-cat locations.

I had read some other threads indicating that with a higher duration ( I have a 228/228) cam it may help to use a rear O2 sensor in the front - but that seems to contradict the info given by the dealer..

Nick Hokie

Below are the GM and AC Delco part numbers, and the locations of each of the stock replacement oxygen sensors. Basically, left side of car = GM part number 25312197 and the right side of car = 25312196.

AC DELCO Part #AFS98
Sensor, HTD OXY (Posn 1) OEM Sensor; Left Hand (driver side); In Exhaust Manifold (GM #25312197)

AC DELCO Part #AFS97
Sensor, HTD OXY (Posn 2) Right Hand (Passenger Side); Front of Converter (GM #25312196)

AC DELCO Part #AFS98
Sensor, HTD OXY (Posn 3) OEM Sensor; Left Hand (driver side); Post Converter (GM #25312197)

AC DELCO Part #AFS97
Sensor, HTD OXY (Posn 3) Right Hand (Passenger Side); Post Converter (GM #25312196)