HeyMan

So I have a problem with my 09 S550 I get a misfire when there is a load so at 3000 rpms and up my car will misfire and multiple cylinders, I’ve replaced all new coils all new spark plugs twice double checked gapped, replaced mass air flow sensor, replaced the whole intake manifold and the gaskets and I’m still having a misfire could anyone help

BOTUS

if the engine management diagnostics doesn't help, a compression test is always a good idea