u/LTOhNo

2011 N51 328i 2wd manual. Was a SULEV.
When I bought this car I immediately knew something was wrong with it. My ‘07 N52 rips compared to how this car ran.
It had to be the catalytic converters but it took a while to get around to replacing them.
Originally I bought stock replacements but after seeing some shitty long tubes for practically free on eBay I threw a set of those in. With Bimmworks stage 2 tune, no cats, EAC and SAP delete the car is very fast. Feels almost as fast as my 2006 GTO. Cats were 100% definitely the issue. If you look at the pics the rear manifold has a white surface from practically melting the exhaust off the engine.
N51 no cats (none), Becker copy of I have no idea whose exhaust and it’s too GD loud.