The 2022 Audi A4 delivers premium sport sedan performance with its refined 2.0L TFSI turbocharged engine. When your A4 displays a P0304 code indicating a cylinder 4 misfire, understanding the TFSI engine helps guide accurate diagnosis.
Understanding P0304 in the A4
The A4's 2.0L TFSI (Turbo Fuel Stratified Injection) engine combines turbocharging with direct injection for excellent power and efficiency. Cylinder 4 is located at the rear of the inline-4 engine, nearest the firewall. The engine control module monitors combustion events with German precision.
TFSI Engine Considerations
TFSI engines are known for their performance but can develop carbon buildup on intake valves due to direct injection—fuel doesn't wash over the valves to clean them. The turbocharged environment also accelerates spark plug wear and demands quality ignition components.
Diagnostic Approach
Access the cylinder 4 ignition coil at the engine's rear. Inspect spark plug electrode condition. Check for boost leaks in the charge piping. On higher-mileage vehicles, consider intake valve carbon inspection.
Resolution Process
Replace spark plugs with Audi specifications. Test ignition coil output. If carbon buildup is suspected, walnut shell blasting or chemical cleaning may be necessary. Address any boost leaks.