Cylinder 6 Misfire Detected

Cylinder 6 is an AFM cylinder on the GM 5.3L V8. A collapsed AFM lifter is the most common cause of persistent cylinder 6 misfire. Check lifter preload with the valve cover removed. If collapsed, replace all 16 lifters. Consider an AFM delete kit to prevent recurrence. Also check the VLOM solenoid for cylinder 6. Your dealer can confirm whether an open service bulletin or warranty extension applies to your VIN. An AFM/DFM delete also needs an ECM tune, and because cylinder deactivation is part of the truck's emissions-certified configuration, deleting it can affect powertrain warranty coverage and road-legal emissions compliance - check your local rules before going that route.

Cylinder 6 misfire on the Pentastar V6. Swap the ignition coil to another cylinder to test. If the coil is good, check for a failed rocker arm -- the Pentastar has a known issue with rocker arm needle bearings failing. If you hear a ticking noise, inspect the rocker arms on cylinder 6. Replace all rocker arms in the affected head. Your dealer can confirm whether an open service bulletin or warranty extension applies to your VIN.

Cylinder 6 misfire on EcoBoost. Perform a coil swap test (Motorcraft). Cylinder 6 is on the passenger side rear -- harder to access. If coil and plug are good, check for carbon buildup on the intake valve using a borescope. Direct injection engines build up carbon since fuel does not wash the valve. Walnut blast cleaning resolves the issue. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.

Cylinder 6 on the VQ35DE is the rear bank passenger side. Swap the ignition coil to verify. If the coil is good, check fuel injector operation with a noid light. VQ35DE engines can develop individual cylinder compression loss from worn valve seals at high mileage. Perform a compression and leak-down test to rule out internal issues.