hurk

Thank you for the reply & a pdf would be great. The Chilton is kinda lacking.

This is one of those cases where it truly makes no sense. I've been doing routine maintenance & after each step the mpg has been unaffected, except for after the cooling system flush. Oil & filter change. Transmission gear oil change. Spark plug replacement. Air filter replacement. Fuel filter replacement. I've done each thing separately & the fuel mileage has been always been 22.5mpg +/- a tad. For the year-and-a-half that I've owned the car it has never been less than 21 & is almost always spot on at 22.5. I get my fuel at the same Cheveron station 99% of the time (87 octane).

The next thing on my list is the IAC & throttle body.
I'll keep monitoring the mpg & look into the oxygen sensor(s).

Thanks again. JMK.