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Q: Cylinder 4 misfire

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Cylinder 4 is misfiring. Code P0304 is shown. Put in a different coil didn't really help. Put in a new spark plug in cylinder 4 it runs better but still throws code and misfires. Car still sounds like is messed up and is shaking. But the one new spark plug did help it. Engine light is still flashing. What else can I do?

My car has 90760 miles.
My car has an automatic transmission.

It sounds like you may need an ignition control module. It’s a small device mounted around the right front of the engine compartment. It has a plug with about a dozen wires connected. The module has a separate channel for each cylinder and sometimes individual channels drop out causing a dead miss in a single cylinder. The module is pretty expensive, and most parts places don’t take returns on electrical parts, so you may want to have it verified before you purchase one. Contact YourMechanic and they’ll send a mechanic to your home to check out your misfiring issue and keep you from spending money on parts that you don’t need.

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