1993 Q - Federal - Exhaust gas sensor?

[Q451990]

"Q1" is a federal model - "Q2" is from CA. The CA model has an exhaust gas temperature sensor bolted in to the plenum port where the EGR valve is attached. The Federal model had a bolt.

I know that the later models, even with federal emissions had the sensor. Does anyone know when the federal emissions started using the exhaust gas sensor? Since I'm running a 93 ECU in "Q2" I'd like to know if it's monitoring the EGR valve function.

Thanks!

Heath

[Q45tech]

California has always had more difficult emissions than other 49 states. 1994 brought us Federal EGR temp sensor to help check for EGR function at cruise speed [2000 rpm].

Everything was planned back in 1988 to meet 1990 and 1996 requirements they just phased in slowly to deal with drivability issues.

The question is how well the temperature sensor monitors the health of the egr system as a translation to egr volume is probably difficult.

We find that it takes about 120k to seal off the egr if lots of steady highway driving is the norm, then progressively less after the first cleaning say 70-85k.

It can get so bad you have to roto rooter the system out with a flexible drill driven wire.

The other problem is that the egr amount required for a new engine is different after the rings wear and the engine get 150-250k on it!

[Q451990]

Thanks Dennis! I was just curious if that sensor would monitor anything with the 93 Federal ECU. I remember seeing it on a couple of 94-96 Q's, but couldn't remember about the later 90-93s.

Heath