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Q: Misfire in cylinder 6. GMC Sierra 1500.

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Replace coil pack,fuel injector, spark plugs, wires. Engine light is on and have rough idle.

My car has 99000 miles.
My car has an automatic transmission.

Hey there. You need to have the engine compression tested to see if you have a leaking valve or rings. You could try to have the combustion chamber cleaned of carbon and see if the problem improves. This may be due to a sticking valve or excessive carbon build up on the intake valve. If compression is low and no leaks are found, then you may have a worn cam lobe. If you would like to have this taken care of, a certified pro from YourMechanic can come to your car’s location to inspect the misfiring problem and have this addressed appropriately.

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