Smog Check and Rear Oxygen Sensors
 

Assuming a car passes the visual inspection, if a car's rear oxygen sensors are deactivated, and its PCM is flashed so no codes are stored and the check engine light is not activated, can it pass a smog check? Thanks.

If it's a 2000 or newer all they do is plug into the obd2 for smog. Make sure the monitor's are ready to pass

The only monitor allowed to be "not ready" is Evap so if the O2 monitor can't run and pass then you will fail even if the engine light is off and no codes are stored.

They do a visual if there is no codes and the O2 sensors are in place you only have to worry about the "sniff-test". In my 1996 LT4 I failed miserably; It was so bad the report said "GROSS POLLUTER". I bought two new California catalytic converters and I passed. The guy said: "It passed super clean"

Check it out, with those CA crap cats, the car is super lazy and I get less MPG.

x2 reaplaced them on my SIlverado it feels like a slug. Prior to that pig used to get wheel hop hitting passing gear with the originals on there.