2004 F-150--5.4l any ideas on what is wrong
Idles low, and will sometimes shut off when in forward or reverse and feathering the throttle (drive through, inching up to stop lights etc...) or stopped. It is only turning about 250-300 RPMs when sitting still. I replaced the throttle body positioning sensor and that did not fix the problem. Any ideas ?? Thanks for all the help

 

Have you cleaned the MAF or the throttle body? How many miles?

 

170k--everything looks clean.

 

They may "look" clean, but did you clean them anyway?

 

I guarantee, with 170,000 they need cleaning. When were the plugs changed?