05 F250 6.0 96K Miles, 1/4 throttle stumble
Just wanted to pick your brains on my truck.
05 F250 96k and is all stock except for a MBRP Exhaust with no cat. Its pretty much ran ruff and hard to shift when cold for quite awhile. I usually let it warm up for a bit before driving it.
Recently, the truck has developed a stumble while driving say 40mph at 1/4 throttle. The truck stumbles then clears and u can see a puff of blue smoke in the passenger mirror.
stuck injector? Clogged EGR ?
Where to start to try and diagnose ?