Hi,

my '95 993 just failed the smog test (Texas).

I've had some O2 sensor issues lately. The CEL would be on sometimes, usually when the engine is pretty hot (after track session, or stuck in trafic). The error code would be 1222, which is an intermittent no signal error.

I changed the O2 sensor 2 days ago, and just tried to pass the state inspection, which are overdue by >2 months. And it failed :-(

The contacts of the O2 sensor looked clean. I have a brand new sensor. So if there's really a signal problem, it's probably not in the sensor itself.

I have a Steve Weiner chip on the car. Does it make a difference ? Should I put the original chip back before smog tests ?
I never had any O2 cel codes without the chip.

The results of the smog test :
High speed test :
HC(PPM) Standard=120 reading=312 FAILED
CO(%) Standard 0.67 Reading 9.99 FAILED
CO2 (%) Reading 9.8
O2(%) 0.0
NOx(PPM) Standard=848 Reading=885 FAILED

Low speed test :
HC(PPM) Standard=124 reading=326 FAILED
CO(%) Standard 0.69 Reading 9.99 FAILED
CO2 (%) Reading 9.9
O2(%) 0.0
NOx(PPM) Standard=937 Reading=377 PASS

Any idea what would cause this ?

BTW the inspector let the car run for a while, he did not stop it during the safety checks, so when he got to run the dyno tests, the CEL came on, and the engine temp was above 9 o'clock.

I'm heading to the track tomorrow for a 3-day DE weekend.
Is it a bad idea to drive the car like this ?

Plus I'll need to get this fixed within 2 weeks.

Thanks for your help !