Im getting an rpm jump when idle at a stop light. Kind of like a slight missfire. Im not getting any codes. I replaced coil packs and spark plugs 20k miles ago. Im clueless to what it could be. Any ideas? This is on a 2007 expedition with 117k miles on it

 

Are they Motorcraft plugs and coils? I'm learning that other brands don't always work as well. Have you had any codes pop up?

 

Motorcraft plugs but not coils. Could that be it?

 

I have this too. Could never find out why.