Ok ive been posting for awhile working on my 91 fbird but it kept stalling i knew that i needed a cat conv had one put in and bam it stopped stalling but it still has a slight eratic idle at stop lights it bounces but its not stalling i replaced the cat plugs wires cap rotor coil air filter fuel filter replaced vacum hoses i have a small oil leak in the valve covers no smoke comeing out of the tail pipes and the car is great while moving any idea on how to eliminate the eratic idle?

also the stalling and bad idle started after i pulled the iac valve and cleaned the trottle body

 

I had a similar issue when my IAC went bad.... I replaced it and the problem was still there. The key to making sure the IAC is working ok(if its a good IAC), is to let the car start and get up to running temp, then remove the ground cable from the batt. for five minuets(reseting the computer) then reconnect the batt. cabel, then start the car back up let it idle 5 min, then drive it like normal for 15 min.

This worked for me, i saw this IAC learning the computer, somewhere in a post before.