- Understanding the P0304 Code: This code specifically indicates a misfire in cylinder 4. Misfires can be caused by various issues including faulty spark plugs, ignition coils, fuel injectors, or even internal engine problems.
- Diagnosing the Issue:
- Swap Components: Since you've already replaced the spark plugs, consider swapping the ignition coil from cylinder 4 with another cylinder (like cylinder 2). If the misfire code changes to the new cylinder, the coil is likely at fault.
- Check Compression: Perform a cylinder compression test. If the compression is low, a cylinder leak-down test can pinpoint whether the issue is with the valves, head gasket, or piston rings.
- Further Steps:
- Vacuum Leak Test: Use carb spray or brake cleaner to spray around the intake manifold and fuel injectors while the engine is running. An increase in RPMs could indicate a vacuum leak.
- Throttle Body Check: Given the model of your car, a dirty throttle body could also be a culprit. Be cautious with the coolant lines if you decide to clean it.
- Professional Diagnosis: If these steps don't reveal the problem, it might be time to consult a professional mechanic for a thorough diagnosis.
- Note on Repairs: It's understandable to feel frustrated about the cost of the spark plug replacement. However, regular maintenance like this can sometimes prevent other issues.
Please login or Register to submit your answer