BMW S54, E46, M3 Fuel Rail

The installation was straightforward once I had the old one off, and the o-rings sealed perfectly on the first try with no leaks. This fixed the rough idle I’d been chasing for weeks, and the fuel pressure is finally steady.

The machined finish on this rail matches the factory look perfectly, and the injector ports seated without any fighting. Took about an hour to swap on my Z4 M Coupe and the idle smoothed right out.

Installed this on my E46 M3 last weekend—the mounting brackets lined up perfectly with the stock holes, no fuss. Fuel pressure held steady right at 3.5 bar on the first crank after I swapped the lines. A clean, direct replacement that saved me from tracking down a used original.