Rear injector replaced about 8k ago (took the
HD mech 5 hours to figure out the injector was bad, another 3 hrs on the dyno to tune afterward). Now the symptoms are back again- OK acceleration, but misses during steady speed, fuel mileage down, backfires and pops. Took the plugs out today, the rear plug is fouled. Think it's just a bad injector (again) or could it be the ECM?