Has anyone experienced a P0304 (cylinder 4 misfire) DTC on 5.3 with AFM that was NOT caused by a stuck value, collapsed lifter, bad lifter solenoid or flat spots on the #4 cam lobes? I have an obvious misfire at idle which makes the engine stumble about every two seconds and I notice a slight RPM fluctuation on the tach. The fluctuation never changes more than 100 to 200 rotations. When it is revved up and held at any RPM it stumbles still, but is not as noticeable. I don't hear any valve-train noise, but while sitting in the truck, I can definitely feel it shaking.
While driving, I don't notice the anomaly AS much, but it is still present. Haven't pulled the #4 plug out yet, nor have I performed a compression or fuel pressure test with leakdowns.
I haven't had any DTC or DIC readings that indicated the traction control or stabilink was malfunctioning, only the P0304 #4 misfire, so I don't suspect, but cannot rule out a throttle body or TPS fault. Doesn't appear to be burning any oil either.
Has anyone ever solved the P0304 DTC with just a spark plug, coil pack or plug wire? I would rather not have to pull the top end off to fix a craptastic AFM issue.
While driving, I don't notice the anomaly AS much, but it is still present. Haven't pulled the #4 plug out yet, nor have I performed a compression or fuel pressure test with leakdowns.
I haven't had any DTC or DIC readings that indicated the traction control or stabilink was malfunctioning, only the P0304 #4 misfire, so I don't suspect, but cannot rule out a throttle body or TPS fault. Doesn't appear to be burning any oil either.
Has anyone ever solved the P0304 DTC with just a spark plug, coil pack or plug wire? I would rather not have to pull the top end off to fix a craptastic AFM issue.
