Mystery Audi TT Misfire :(
Car: 2006 Audi TT Mk2 (8J)
Body: 2-door coupé
Engine: 2.0 TFSI petrol
Engine code: BWA
Engine family: EA113
Mileage: ~110,000 miles
Drivetrain: Front-wheel drive
Transmission: 6-speed Manual
Situation: Engine misfires on cylinders 1 & 4, only at idle. Misfire occurs more on cylinder 1, roughly 10:1 ratio to cylinder 4 according to my VCDS live data. If I raise the revs to about 2k then the count stops rising and returns to 0. Engine light used to come and go at the beginning but it's always present now. The rpm is stable at idle, the needle doesn't fluctuate. Car hesitates to start in the winter but it's fine during the summer. I could feel the misfire while sitting in the car a lot more during the winter but it's a lot better now. Car drives fine otherwise with no loss of power. I have been ignoring the problem for a bit as it wasn't really bothering me but now the engine light will fail the MOT so I'm looking to get it sorted. Any help would be appreciated.
Fault codes: P0300, P0301, P0304
Work done so far by myself:
• Replaced PCV valve + hoses
• Replaced PCV valve gasket
• Compression test showed consistent pressure
• Swap tested and replaced spark plugs - misfire doesn't move
• Swap tested ignition coils - misfire doesn't move
• Swap tested fuel injectors - misfire doesn't move
• Replaced injector O-rings and Teflon seals
• Performed manual carbon cleaning
• Replaced intake manifold gasket
• Replaced purge/N80 valve
• Smoke test shows no leaks
P.s. This is the first ever car I have owned and worked on with no prior knowledge, just 100s of hours of watching videos on youtube, reading through different forums and AI lol