So a customer has a CTSV gen 3 with the LT4. Car is full bolt ons and it was tuned by a big internet tuner (not saying this is there fault by any means). Customer brought the car in with a miss fire on cylinder 5. We changed the plug and checked the wire. Everything looks good but it's still miss firing. On the scanner it looks like it could be because it's pulling timing at idle. -5ish degrees. Could the Nick Williams throttle body be the culprit (its been on the car for about two years)? Could it have gone bad? Is there a way to relearn the throttle body to the ecm with the HP scanner? Any other tricks? I added like 50 rpm to the idle and let in some more air but it didn't seem to change anything.