I have a supercharged v6 m112k amg engine and the right bank seems to be having issues first it broke the interior pipes of the header and now the cat is fucked or atleast smells like its fucked, its got that classic “i really shouldnt be breathing these fumes” or dirtbike exhaust type of smell, the thing is, the ECU is not throwing codes, lambda voltages are relatively consistant long term fuel trim is showing -4,7% left and and -5,5 right and the same injection time on both banks. Im a bit of a noob when it comes engines but when i had it apart i did a quick leak down test and everything seemed “decent” for 160k miles and the engine runs completely fine, so why would i be having these issues? Any input is greatly appreciated :)