E39 M5 and E52 Z8 Discussion
I've done a search, but it recovered about a billion threads about high flows cats.
So, i have Milltek High Flow cats in my car, after a week of use (150~200miles) i have a SES (CEL, Engine Management) Light.
Peake plugged in, codes pulled, b2&b3 Catalyst Efficencys
So, what have...