[Nightfire]

Hey everyone, looking for info on the NPP valve. I notice my Driver side doen't close when I put in stealth / snow ice mode but Passanger side works fine. If I remove the valve i can rotate the metle disk. If I start the car it moves/rotates all the way left. If I change modes it does move at all when it disconnected and not sure if it suposed to. If car is on and I try to rotate it it will not or it fights me to stay in the same postion. My question is, will it rotate when not connected to the exhust and does it need to be relearned somehow?

[bishopts]

I would think it would be like any other actuator and do a sweep to learn it's stops if it didn't know them. Maybe try disconnecting the battery for a few mins to see if it trys to relearn.
I have an NPP muffler but my car didn't come with it so i won't be able to help figure this one out with you.

[beowulf556]

How about switching the actuators and see what the valves do? Then you'll know for sure if it's a valve issue or actuator.

The actuators should still move even if not connected to a valve.

[dmcmahan60]

My buddy had this problem and he had to take it to the dealership and pay $125 to have the NPP valves reprogrammed.