The P0304 code in your 2020 Mercedes-Benz GLC indicates the engine management system has detected persistent misfires in cylinder 4. With potential accumulated mileage, understanding both standard causes and wear-related factors helps target diagnosis for this luxury SUV.
Understanding P0304 in the 2020 GLC (X253)
The 2020 GLC X253 offers the M264 2.0L turbocharged four-cylinder in most variants. This inline-four positions cylinder 4 at the rear. With several years of service, these vehicles may approach standard maintenance intervals and show age-related wear patterns.
Age-Related Considerations
Vehicles from 2020 may be approaching spark plug replacement intervals. Ignition coils degrade from years of heat cycling. Carbon buildup on intake valves accumulates progressively with direct injection engines. Consider the vehicle's mileage and maintenance history.
Diagnostic Process
Review available maintenance records. Use Mercedes-compatible diagnostics for comprehensive data. Inspect spark plug condition noting age and mileage. Test ignition coil output. Carbon buildup inspection benefits higher-mileage vehicles.
Repair Solutions
Replace spark plugs if due or worn. Address carbon accumulation through professional cleaning if indicated. Replace degraded ignition coils. Quality components maintain Mercedes character.