CUSTOMER CONCERN Engine misfires with DTCs P0301 and P0302 while the transaxle produces a severe chattering noise. CAUSE Coolant was visible inside a cylinder during borescope inspection, confirming a leaking cylinder-head gasket; the engine misfire caused the transaxle chatter. CORRECTION Remove the cylinder head, replace the failed head gasket, refill and bleed the engine cooling system, clear DTCs P0301 and P0302, and verify smooth engine and transaxle operation.

CUSTOMER CONCERN The engine misfires on cylinders 1 and 2 with DTCs P0301 and P0302, and the driveline produces a severe chattering noise. CAUSE The confirmed repair identified a failed cylinder-head gasket; coolant loss after sitting and a startup misfire supported coolant entering a cylinder. CORRECTION Remove and replace the failed cylinder-head gasket, clear P0301 and P0302, and verify the engine starts and runs without misfire or driveline chatter.

CUSTOMER CONCERN The engine misfires with no compression on cylinder 3, no oil registering on the dipstick, cylinder-misfire DTCs and P1286, P128A and P2646. CAUSE Testing confirmed internal engine damage with loss of cylinder compression associated with severe oil consumption. CORRECTION Remove and replace the damaged engine assembly, clear all stored DTCs, and verify compression and normal engine operation.

CUSTOMER CONCERN The engine runs very poorly after air-filter service, pings under load, remains in open loop, and stores lean and misfire DTCs. CAUSE Inspection confirmed debris contamination on the mass-airflow sensor element, causing incorrect airflow measurement and the lean misfire. CORRECTION Clean the mass-airflow sensor element and air-filter housing, clear the DTCs, and verify closed-loop operation and normal engine performance.