Intermitant low idle

[freemanroberts]

I recently had my plugs changed and fuel filter replaced along with a new pcv valve.

I had thrown a lean bank code and it turned out to be the fuel filter as I had guessed.

Problem is when I got it back it was idleing lower I pointed it out and they seemed unconcerned. Now after a good warmup it
Intermittently drops to 500 rpm and starts to surge when in drive. It seems fine for a min or two then suddenlly drops to 500 then goes back up and is fine for another little bit and is throwing no codes

I assume you are gonna say it's the idle air control or IAC but what are the chances it picked right then (when the plugs were changed) to go?

Is an IAC usually a steady problem or will it jump from bad to good and back like mine?

 

[SPreston2001]

Id say its your EGR valve or the IAC. Maybe after you replaced everything it exposed another weak link that you probably didnt notice before. Either that or the people that worked on your truck screwed sumthin up.

 

[AvroAero]

I think my IAC had problems before I got rid of the truck and it was minor intermittent.

 

[green03]

I vote IAC