Do the O2 sensors have to be exact matches? on 2002 Saturn LW200

Front O2 sensor original, does not test bad.
Rear O2 sensor tests bad.
If I replace the rear sensor with one from Carquest will it affect engine performance?

Asked by for the 2002 Saturn LW200
Saturn will of course say you must replace the sensor with one from them. The rear O2 sensor monitors catalytic converter efficiency and is slightly less critical than the front O2 sensor. Use a "brand name" "factory type electrical connector" and you should be OK. Carquest may have a Delphi sensor which are good, NGK, Denso also good makes.
1 more answer
Purchase a Bosch Universal O2. It comes with detailed instructions on how to install it. The part # is 15733. It will cost about $75.00.