Mongo

I did a search, but never really found a definitive thread on this. How does cam timing (advancing or retarding) affect emissions on the 32-valve cars?

I'm currently set at 2 degrees advance for my auto. I have smog coming around and have always had a rich running car with very low nox. Should I be expecting different A/F numbers thanks to the intake valves closing earlier?

davek9

At what RPM do they do the test, this would matter with Cam timing, yes?

As it has been almost 14 yrs for me to have one required and sure things have changed.

Mongo

Since mine is an auto, it's somewhere around 1500-2000 for the 15 mph and 25 mph run on the dyno.