bobl

Yes all 502 MPI engines have knock sensors. You need to verify it is working correctly.

alter ego

I thought about that but I didn't think it had a knock sensor. It doesn't seem to be working if its there. I ran yesterday and picked up 400 more knock free rpm. Small step but it seems to be running better across the whole rev range. I tool your advice and ran a little additive and topped off. At first it ran pretty bad, I don't know if it liked the additive much but after a little bit it cleared up some. Thanks everyone for your help.