[Chevy_Thing]

2012 Impala with 122000 miles. Ok so last week I was driving my car and it started misfiring but not too bad, just a slight vibration and throwing a p0302 code so I figured I would replace the spark plugs since it's been awhile. After I replaced them, it starting running very rough. I didn't even want to drive it. Also threw the p0300 code and the p0302 code went away. Today I replace all the ignition coils and it's still doing the same thing. Any ideas on the next thing at look at?

 

[Dfelt75]

This maybe a long stretch but possible intake manifold leak.. Try spraying start fluid/carb spray along intake manifold with engine idling and listen for change in engine speed. Go all the way around it.

Another possible cause...check rubber boot that holds MAF sensor for tears/cracks

 

[Chevy_Thing]

This maybe a long stretch but possible intake manifold leak.. Try spraying start fluid/carb spray along intake manifold with engine idling and listen for change in engine speed. Go all the way around it.

Another possible cause...check rubber boot that holds MAF sensor for tears/cracks

Thanks. I ordered a new intake gasket from Amazon for the hell of it but ill try that.