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  1. E39 M5 and E52 Z8 Discussion
    Hi All, 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...