2001 Mustang 3.8L random miss

130K No cats, no sims , new wires and plugs the old plugs were clean and normal. Fuel pressure 50psi, have road tested will miss randomly at idle-or under load. Will stop if AFS is unpluged but will come back. Its a new AFS. Check air bypass, EGR and replaced eletronic control sensor for EGR. Cleaned throtle body. Vacume reading 17in. Motor has a squek. Have removed belt to try and find squek. Sounds like lifter area. Will do compression test next.

PCM had chip in it for many years. Removed chip and all is well.