If your car finally runs well, I'm glad for you because its about time.
First swap in teh world, lol.
Guys been swapping S54s in non-m all along and not much is needed to install an HPF kit, its so idiot proof that I can imagine anyone should be able to install it as it sells as a bolt on kit.
Simply because it took them soo long to finish the job and they needed to many tries to make it all work makes them look like they dont know what they're doing.
If you dare, share with the rest of the community how long it took to get the car running well, lol
I saw your car at bimmercruise, it didnt run well at all to say the least.