I have a 2003 Yukon with the 5.3. when it idles the RPM's drop to about 400 and it almost dies. I have replaced plugs and wires but the issue remains. anyone experienced this?

Thanks

 

no codes? do you have access to a scanner? fuel pressure/volume and vacuum leak are common places to start

 

correct no codes to follow up on

 

clean maf and throttle body and iac?
i just cleaned mine minus the maf (was done recently anyways) and my idle went from 500-550 to 620-650

 

Mine is an 07 with 227k on it and it does this almost daily? I've cleaned the throttle body and mass air sensor with no change. No vacuum leaks last time I let my ocd get the best of me. I believe mine idles so low that the alt can't keep up with what the BCM is telling it to output and the headlights will go dim? I figure it's just getting old and until it throws a code there's not much I can do.

 

fuel pressure, fuel volume, fuel trims are always my start points with idle issues unless theres a code saying to go a different direction