hey guys, got my car fixed....new tranny and getting ready for the mpfi convert...but i am having a problem...i get it back from the garage and everything is awesome! (its amazing what a stopped up cat can do to your car)...but now when it idles it rev up the down the up then down...and if i put it in first it seems go without me touching the gas...i messed around with the throttle cable but never had any luck..the mechanic thinks it may be a 02 sensor or something? its driving me crazy..any one have any thoughts?

 

first thing would be to check for vacuum leaks.

is the ecu throwing any codes?
you might also want to check the pcv valve. that was the cause of my idle surge (although at the time i had no pcv valve)

 

if youve messed around with your throttle cable then you probably messed up your TPS voltage. check the voltage with the throttle fully closed and fully open. 4.5v open & 0.45-0.5v closed.