I finally fixed the erratic idle on my 2001 f150xlt 4.6 with 58K. I've changed every sensor in the book and it turned out to be plugs. My #3 plug had oil on the top part of it and i assume this could have caused it. Also some of the plugs were white. The plug with oil on it was hopefully from the me spilling oil and not a leak. Anyways the plugs were the fix. I also installed the superchip 1715 today and the K&N intake. Feels nice but shift kinda hard even after I fix the hash marks. Oh well. Any ideas would be great.