Any other codes? P0304 is just a misfire code. How many miles have you put on the new plugs and coils? I'm stage 2 and replace both my plugs and coils every spring since it's cheap enough.About a month after I bought my car 3 years ago, I started my car and headed to friend's house. 3 minutes after my car started shaking, lost power, and CEL started blinking. I was right by an auto parts store so I conveniently parked there and quickly learned I had to replace an ignition coil.
Shortly after that I ordered a set of coils and spark plugs. No problems after that.
Last night I was driving back home. First 5 minutes were fine, then all of a sudden CEL and ESC lights came on while I was on a freeway. I started feeling the whole car shake when I was going up smaller hills. When I got off the freeway after about 20 min, the car was shaking a lot more at the stop light and more lights came on the dash (ABS, and a few others). P0304 was throwing with some of the others. When I started accelerating the car would jerk and shake a lot, the transmission wouldn't shift until around 4k RPM. It was a mess. Felt so bad I drove it like that for ~20 miles.
I assumed it was the same issue as 3 years ago and ordered the parts. Haven't touched the car since.
Should I be worried it's something else or does it sound like the symptoms? The parts aren't arriving until Friday so I'm in suspense. Anyone had the similar issue?