Severe misfire and rough idle with GTI

[GTIDriver2024]

Hello everyone! I have been having these issues with my car.
- severe misfire, especially at idle (sounds cammed and occasionally pops).
- popping noises when decelerating at low speeds and RPM.
- slight rattle noise under heavy throttle above 3,000 RPM.
- misfires mostly on cylinders 2 and 3
It is annoying that I have no stored diagnostic codes.
Even after many fix attempts as
- replacing spark plugs and PCV valve.
- swapped ignition coils (misfire didn't move).
- cleaning MAP sensor;
- no vacuum leaks;
- logging short-term fuel trims;
- a good condition of the high-pressure fuel pump, the car stays in the same status without allowing me to understand any clear cause. Any thoughts, please?

 

[VWIGTI1111]

I kinda have the same issue on my AWP. Hoping someone will see your post and add some thoughts...

 

[Jaggs]

Since you’ve ruled out the basics, could it be a timing issue or clogged injectors?

 

[Bloody_Baron]

Sounds like you’ve covered a lot of the basics already! Since the misfire didn’t move after swapping ignition coils, I’d start looking at injectors next. Have you checked for a clogged or failing fuel injector on cylinders 2 and 3? If they’re not spraying properly, that could cause rough idle and misfires without throwing a code.

 

[Stargazer99]

I'd definitely start by checking your cylinder compression or doing a leak-down test to see if there's anything going on with the valves or head gasket. That rattle you're hearing when you accelerate hard could be a sign of a bad timing chain tensioner which can definitely cause misfires. even though the fuel trims look good, it's worth checking the fuel injectors on cylinders 2 and 3 like what @Bloody_Baron said.