Jaguar Repair: rich of lean mixture, ca emissions, airflow meter

Question
Howard, My timing is right on, new fuel is both tanks my cats were replaced two years ago with the 02 sensor, am I rich or lean? This car was a gift and it is in immaculate shape, I picked it up in Oceanside Calif sea level, and they had just had it tuned to pass Calif emissions, now I'm at 5200 feet in Arizona so I would think I have a rich mixture, to me that means turn the screw in to lean it out?

Answer
If you passed CA emissions and moved to 5200 ft you probably are rich and you need to turn the mixture screw out (counter clockwise)(the mixture screw is an air adjustment not a fuel adjustment)
Even though you don't have a MAP sensor the airflow meter will counteract the lower density air by not moving in as much so that will help at higher RPM and the 0-2 sensor will help. The only thing that will fight against you will be the pressure regulator since the lower vacuum produced by the thin air will tend to give you higher pressure. (richer mixture) You need to test it. 32 to 35 PSI is normal running. 42+ with no vacuum.
Howard