Code P0301, misfire in cylinder one

Good morning,

I would start by checking the compression to be sure nothing is wrong with the cylinder. The compression should be 140-160 pounds.

https://www.2carpros.com/articles/how-to-test-engine-compression

As far as the testing. You need a test light, not a voltmeter for checking the injector. You need to check for voltage at both wires to the injector with the key in the on position.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

As far as the coil, you need a scope to test the output of the coil. You could try and switch with another cylinder and see if the miss travels to that cylinder.

Do the compression test first.

Roy

I don’t think it is a compression problem because the misfire started right after I had the sparks plugs changed.

I would still start there.

Roy