So this all started when my girlfriend was driving her GTI up a hill one day and it started shaking at low rpm and running very rough at idle. When you first turn on the car you get low power until EPC light comes on, then the check engine light stays solid. VW dealer first changed the sparks plugs and coil packs, which didn't work. They then said it was the intake and put something in her car that was suppose to clean it out. Car still runs the same.
I hopped on google last week and went through forums to see if I could figure out the problem. I changed the PCV valve and fixed the rough idle, but the car still shakes badly when you give it gas up until 2,800 rpm. Also when the car is cold the shaking is minimal, and as the car warms up it gets worse.
When the shop looked at the car they said the only faults they had were cylinders 1, 3, and 4 misfiring. This was before the PCV valve was changed. I followed another forum guide to continue troubleshooting which said to look for carbon build up and then the fuel injectors. So I pulled out the intake, it didn't look to bad, but cleaned it up and changed all four fuel injectors. No change, not sure what to do with the car now, so this is why I'm here... help!