The P0302 trouble code on your 2018 BMW 3 Series indicates that cylinder 2 is experiencing misfires detected by the engine management system. The F30/F31 generation 3 Series uses the B48 2.0L turbo in 330i or the B58 3.0L turbo in 340i models. These direct-injection turbo engines have well-documented characteristics for diagnosis.
F30 Engine Platform
The 2018 model represents the final year of the F30 generation. The B48 produces 248 horsepower while the B58 delivers 320 horsepower. Both are inline configurations with cylinder 2 second from the timing end. Direct injection is standard, with established maintenance requirements.
Common Misfire Causes
By 2018 mileage, carbon buildup on intake valves may be significant on direct-injection engines. Ignition coil degradation from heat and age is common. Spark plug wear reduces ignition energy. High-pressure fuel system issues including injector deposits affect fuel delivery. Vacuum leaks from aging hoses can cause misfires.
Age-Related Considerations
The 2018 model year is now several years old with potentially significant mileage. Age-related component wear affects ignition system reliability. Carbon buildup from direct injection may require cleaning. Vacuum hoses and gaskets may have deteriorated. Comprehensive diagnosis should consider age-related factors.
Symptom Recognition
The sport sedan displays rough idle, vibration, and hesitation with misfires. BMW's driving dynamics suffer when cylinder 2 doesn't contribute properly. Check engine light accompanies the condition.
Repair Solutions
Replace spark plugs with BMW-specified units. Replace ignition coils as needed. Clean carbon from intake valves using walnut blasting. Service fuel injectors. Address any vacuum leaks discovered.