Running half a can of seafoam in the crankcase and half a can in a full tank will clear a bunch of the top layer carbon deposits. Might free up your oil rings if there's any tension left in them.
Just pull the bulb out of the check engine light lol. Or, I know guys that used to wire the check engine light bulb in with the battery light bulb. that way when you turn the key on, engine off, the CEL would turn on like normal. but no more pesky CEL.
so what ended up being the fix? hopefully it stays fixed!