Ford Raptor Forum

Sounds like it may be spark knock. I would flash it back to stock and re-evaluate to see if it’s a tune issue

I can do that. I've had no codes appear and I'm running the stage 1 91 octane tune with COBB intake. If it goes away after reverting back to stock would you suggest changing plugs and trying again?

I would ask your tuner if you can datalog the issue and send it to them. You’ll want to verify that something more serious isn’t happening before going any further, spark knock is very damaging.

I also just read one of your comments about using E10 fuel. I've always used ethanol free fuel so that may be a contributing factor

Well I think the issue presented itself yesterday. Under mild acceleration the passenger side boost pipe blew off the turbo. I'm guessing this is where the sound was coming from. I reconnected everything but now I'm getting zero boost at all. Showing -10 on the boost gauge. I will remove the pipe this evening and check to make sure the turbo is spinning. It appears that the wastegate is open now. Any insight?