Air fuel control derate?

[Brewster64]

Just my 2 cents, but mine was derating here and there, finally threw a code. Was fuel shutoff selenoid. 50 bucks, cheap fix, no more problems. Also, it was starting to run on after key off. Last time it did that, it never derated. Had a shop change that one to stop run on. Did this one myself on the road, and guess what, shop that did last one never cleaned anything up on the little block, and plunger, so it was hanging up in there.....hmmmm, stealerships!