The EGR orifices in the intake manifold may plug with sludge. If the truck has high mileage, this may cause engine misfire when first accelerating because too much EGR gas is directed into the cylinders of the unplugged orifices. This makes the mixture lean, which causes a gradual stumble that increases in severity until repaired.
Average mileage: 113,699 (25,798–215,000)
Exhaust & Emissions affected: V6
7 people reported this problem