Checked the Evap sensor over the weekend by capping the port at the throttle body, and still it goes up to neg 22.7 on ltft. Checked for loose vacuum lines from the map>T>fp regulator>BBS- all good. At this point, I believe I've checked or replaced all the usual/ potential suspects for a rich condition other than the gas cap and the ICM & coil packs. I seriously doubt it's the gas cap, but cheap enough to replace, I suppose, and I've never heard it "hiss" when removing it. GM coil packs and ICM are a chunk of change I'd rather not spend, unless parts off of a JY car are more likely than not to last at least a few months. I also have not checked compression, but with the car otherwise pulling hard and not having any notable performance issues (other than the occasional moving 2-4 misfire count, leading me back to the ICM), I can't see a lot of reason to think there is a compression issue.
