Ive got a 99 devile that just turned sixty thousand a couple days ago. Starting yesterday its starting to die when idling in gear. Sometimes it happens, sometimes it doesnt but its frequency is increasing. Any body ever deal with somthing like this before?

Idle Air Control module?

is that somthing I can change myself? Is this common?

My 96 DeVille (85,000) is statting to do the same thing. Will be sitting at a red light or at a stop sign in D and it will be idling at 650 to 625 rpm's, go down to 600, and sometimes cuts out. Put a bottle of dry gas in, didnt help. Replaced the fuel filter (was origional from the factory) - didnt help. Im thinking the Idle Air Control valve...priced just right at $107 from Advanced Auto Parts

I had that problem with my 96. It was the fuel pressure regulator.

lawlert I'm having the same problem with my 2003 deville.