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Q: How can I find out what exactly is happening in my misfire?

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I diagnosed my car and got a code P0301, it said my first cylinder had bad combustion, dolt know exactly what that means. I asked around and I was told that spark plugs are common failures, I changed them but didn't make a difference, anything else I can do?

My car has 250000 miles.
My car has a manual transmission.

A: Hello there. Misfires are a common problem ...

Hello there. Misfires are a common problem with your 1997 Subaru Impreza as the vehicles ages. The most common failures are the spark plugs, coil, plug wires, fuel injectors, fuel pump, vacuum leaks, or an oxygen sensor. You have done well in replacing the spark plugs first as they are commonly the at fault component.

If you replaced the spark plugs and the fault is still present, the vehicle will need a proper diagnosis to determine what is causing the misfire. A qualified technician, such as one from YourMechanic, will be able to diagnose the misfire condition and proceed with any repairs required to resolve the issue.

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