ok, i had my friend ckeck my car with his scan tool and it gave me a code for an idle air control... i changed it and cleared the code and it pops back up a week later, now its giving me the same code again... whats up with that?

 

It would help to know the symptoms, also a little bit about the car's history: It's not the same if you got it at a police auction for $45 as it would be if you're the first owner and the car was always serviced by Mitsubishi!

The manual isn't very clear about IAC codes: They say something like this means the computer can't set the IAC right, but does the computer know that from the 02 sensor results or ??? However, things that occur to me would be cruddy throttle body (throttle provides some air even at idle, if cruddy then IAC might not be able to open enough), throttle stop screw has been diddled (it's NOT an idle RPM adjustment), or possibly a throttle position switch that's bad or incorrectly adjusted.