Join Date: Dec 2008
Location: Hickory Tavern, SC
Thanked 444 Times in 285 Posts
Very curious to see what you find as I have a shop truck with very similar symptoms.
Replaced IPR and ICP sensors with new ones and it doesn't cure the issue.
Replaced the HPOP about a year ago.
It always idles roughly with ICP between 485-525 and codes show nothing related.