There's only a few catted downpipes that won't throw a CEL, the ActiveAutowerke is one and they're pretty expensive. I had bought a VRSF catted DP but returned it after reading multiple accounts on various sites that it would cause me to fail the annual inspection where I used to live. I never did replace the OE DP. Given the tight space on that side of the motor I'd imagine you'd need a specific one for your ride.

Everyone I know who's installed a catless DP eventually removed it because of the strong exhaust stink.

The charge pipe seems pretty model-specific. I bought an aluminum one that's specifically made for a manual non-Xdrive F30. The plastic OE one blew up on me and was replaced under warranty, and I never got around to installing the metal one that's sitting in a box. Allegedly BMW redesigned the CP to be less prone to fail, usually right at the join to the intake.

Not doing any further mods to that car because it's got enough power for me. The motor has the mild BMW MPPK tune and MPE exhaust which has a nice bark to it.

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