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Q: P0301 code, steady misfire.

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Wife came home with the car having a steady missfire and check engine light on. Never had a problem with it before, been running great. After scanning it showed P0301 "first cylinder missfire." I have since changed the #1 coil pack and all 6 spark plugs without any change. I am 31 years old and none of my vehicles have been wrenched on by anyone other than me for 13 years, but this time I may have to take it to the dealer. Can I take out the fuel relay and crank the motor while the intake is off safely? How else can you determine if the #1 plug is getting spark?

My car has 100000 miles.
My car has an automatic transmission.

A: Hey there. In order to check the cylinder f...

Hey there. In order to check the cylinder for spark you have to remove the coil and insert a spark tester into the coil after reconnecting it. Then you can check to see if it has spark. The injector will need to be checked with a noid light to see if it is getting injector pulse. If you are getting spark and injector pulse then you may have a clogged injector or low compression on the problem cylinder. The most common problem is a clogged injector. If you need assistance having this checked, a qualified professional from YourMechanic diagnose the misfire and follow through with proper repairs.

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