Reply To: 04 gmc envoy 5.3l

[Jeff Moore]

I checked the o2 sensor readings after I replaced the intake gaskets found the gaskets leaking some. The bank 2 sensor 2 on both sides read .925 volts at 99% at start up and do not change even when it goes to open loop. Then bank 1 sensors seem to be reading ok. I took the exhaust loose from the engine to see if the cats where stopped up no change.