Cylinder 1 Misfire Detected

Cylinder 1 misfire on EcoBoost is usually a failed ignition coil (Motorcraft). Swap the coil from cylinder 1 to cylinder 3 -- if the misfire follows, replace the coil. If not, check for carbon buildup on the intake valve using a borescope. Direct injection engines are prone to this. 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 1 is an AFM cylinder on the 5.3L V8. A collapsed AFM lifter is the most likely cause. Diagnose by checking lifter preload with the valve cover off. If the lifter is collapsed, the entire set of AFM lifters should be replaced. Consider an AFM delete kit to prevent recurrence. 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.

Single-cylinder misfire on cylinder 1 is typically a bad ignition coil (Denso). Swap coil from cylinder 1 to another cylinder to confirm. If misfire moves, replace the coil. Also replace the spark plug in that cylinder (NGK). Check for oil leaks into the spark plug tube from the valve cover gasket. 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.

VW TSI engines have carbon buildup issues on intake valves from direct injection. Cylinder 1 runs hottest and fouls first. Check ignition coil first (swap test), then borescope the intake valve. If heavily carboned, walnut blast is required. Also check the PCV valve -- VW revised the diaphragm design.