Okay so i know there are threads about this already but they didn't help because i have done what they said already so any advice would help. I have an 02 wrx wagon Stock. The CEL came on about a month ago so i ran the codes and the P0301 was the only one that came up so i changed out my plugs, but thanks to the morons at autozone put the non turbo plugs in so it came on again but still only on the #1 cylinder so i got some double platnum plugs and moved the coil packs around and everything was good for about a month. Out of no where Yesterday my CEL came on again so i went and ran it and its she same code P0301.
Could it be the Pack wires? or do i need to think more expensive like injectors?