E46 M3 Mysterious Misfire! Any ideas?

Good day my fellow BMW enthusiasts,





I've been dealing with a misfire issue that is giving me headaches as I'm unable to find out the reason why it is causing the misfire. Any help here would be much appreciated!



So I've done most of the basic mechanical fixes include:



-Plugs

-Coils

-Injectors flush

-Compression test

-Fuel filter

-Fuel system cleaner x 2 (on two tanks)

-Oil cover gaskets



After the above I figured it was an electrical problem, and therefore did:



-Wiring test

-ECU reflash





Results still the same, "Cylinder 6 misfire". The ONLY temporary fix that I've discovered is resetting the ECU, that will give me 15kms of normal driving until the misfire comes back.



Any suggestions?



Thanks in advance!

-Leo