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.

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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