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Q: Misfire on cyl. 4

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I have a random misfires on cyl. 4. I have moved plugs, wires, and ignition coil packs to see if the code would move but it still remains on cyl. 4. Start up is the worst, once it gets warm it seems to be fine.

My car has 80000 miles.
My car has an automatic transmission.

You may have a clogged injector and carbon build up on the valves. Have the injectors cleaned out using a professional machine and cleaner. Then have the combustion chambers cleaned to try and dissolve some of the carbon build up on the intake valves. If it still misfires then have a compression test done to see if cylinder has problems with the piston or valves. If you need any help with this, consider YourMechanic, as one of our mobile technicians can diagnose your misfire and help you fix it accordingly.

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