GM engine reduced power issue! Shorted 5v reference circuit. Chevy Tahoe

[@warrenthomas2275]

Yup, BUT ALSO- check that main harness where it lays along the drivers side valve cover. There are 1” tall studs that hold the coil pack tray, they poke straight up and chew through the plastic loom, grounding out any number of sensor wires. My PO641 affected HVAC sensor, alternator signal wire, and finally Accelerator sensor. My throttle went to 3500 with a mind its own. Crazy GM didn’t put some kind of plastic caps on those studs and just laid that massive harness over the top of those. This has to be getting more common problem as these popular models get older.

[@thepitstop9421]

Yes you’re right! I’ve ran into that issue before as well !