Hi I have a 2003 Gallant with 80,000Kms. when driving the car and I come to a stop the idle drops to below 500 like it will stall but then recovers. It does this 50% of the time roughly, any ideas? I haven't disconnect the battery or done any mechanical repairs in sometime.

Alberto

Sounds like a vacuum problem. Check the plastic vacuum hoses and linkages to see if any have cracked or perished.

change the spark plugs and plug wires

check out ..... Resetting Ecu & Idle Correctly 8 Steps..... worked for me

adjust your throttle cable so your RPM are running at 900 at idle. then adjust your throttle body idle screw so it tunes the RPM down to around 750. if this does not fix your problem than you need to do a vacuum check.

I have exactly the same problem with my galant. When I idle, usually after crusing at high speed, the tachometer dips severly below 500, makes noises, shakes the car, then comes back to normal idle at like 800 and stays there. I haven't figured out what it is yet.

Try removing the air inake from the throttle body to check for dirt and gunk build-up on the throttle body. Mine was pretty nasty. I cleaned it with throttle body cleaner and it corrected the low idle problem.