A P0302 code on your 2023 Subaru Ascent indicates the engine control module has detected misfires in cylinder 2. The 2023 Ascent continues with the 2.4L FA24F turbocharged boxer four-cylinder producing 260 horsepower. This direct-injection turbo engine has well-documented diagnostic characteristics.
FA24F Engine Continuation
The Ascent maintains its proven turbo boxer powertrain. Cylinder 2 is on the passenger bank of the horizontally opposed four-cylinder. The turbocharged direct-injection system provides ample power for three-row SUV duty. Diagnostic approaches are established for this engine.
Common Misfire Causes
Direct injection carbon buildup develops over time. Boost pressure irregularities affect combustion consistency. Ignition coil degradation from turbo heat and pressure stresses is common. Spark plug wear accelerates in turbocharged applications. Fuel injector problems affect delivery.
Symptom Identification
The boxer turbo's distinctive sound changes with misfires. Rough idle, vibration, and hesitation affect the family SUV's driving experience. Check engine light accompanies detected misfires.
Diagnostic Process
Scan for all codes including boost codes. Access cylinder 2 on the passenger bank. Test ignition components. Verify boost system integrity. Borescope inspect intake valves. Test fuel injector. Compression testing verifies health.
Repair Approach
Replace ignition components as needed with turbo-appropriate parts. Address carbon buildup through cleaning. Repair boost system issues. Given the newer model year, warranty coverage should apply to defect-related issues.