Clutch test:
deserted road:
accelerate easily to 15-20mph.
shift to 5th
floor the car.
Do the REVS climb while the car's speed does not?
If so, the clutch is slipping. time for a replacement.
as for the rev's I would look at the IAC as noted by Kremit.
ALSO: Autozone and other parts stores scan CEL's for free (except CA), so don't pay $80 for a "diagnostic" scan. Unless they tested Exhaust gasses, and more, it was a waste of money.
