A P0304 diagnostic code on your 2016 Toyota Camry indicates the powertrain control module has detected repeated misfires in cylinder 4. The 7th generation Camry is known for exceptional reliability.
2016 Camry Engine Options
The 2016 Camry offers the 2.5L 2AR-FE four-cylinder (178 hp), 2.5L hybrid, or 3.5L 2GR-FE V6 (268 hp). On the inline-4, cylinder 4 is rearmost. On the V6, cylinder 4 is on the rear bank.
Typical Causes
- Ignition Coil Degradation: Common at this age
- Spark Plug Wear: Likely past service interval
- Fuel Injector Issues: Deposits from years of use
- Vacuum Leaks: Aged gaskets and hoses
- Compression Loss: High-mileage wear
Diagnostic Process
Use a Toyota-compatible scanner for diagnostics. At this age, component wear is expected. Monitor misfire counts. Test ignition components systematically.
Repair Recommendations
Replace ignition coils and spark plugs if not recently done. Clean fuel injectors. Repair vacuum leaks. Compression testing verifies mechanical condition.