[Max335d]

2011 335D. Wanting to install an exhaust without deleting the DPF system or touching the downpipe so just a downpipe back exhaust. I saw the ATM exhaust and was thinking of doing everything from the downpipe back which would mean removing the scr filter. Would this throw any codes? Is there any O2 sensors? Would I need a tune? Or can I install this and run it fine without any lights or tune? I know it’s a secondary “ filter “ So I’m not sure if it’s monitored or what will happen if I delete it without a tune and run that for a while.

[lnxguy]

Yes it will throw codes, yes you would need a tune if removed. It's apart of the emissions system.

[BradleyN55]

What is your goal, the sweet sound of the M57?

If that is what you are after just do a muffler delete, the car still purrs like a kitten but will have a nice grunt under power.......No codes or lights.

Of jus go nuts like I did and delete everything lol.

[lnxguy]

335D mufflers are straight through from the factory. Removing it will make basically no difference. Even just removing the SCR won't do anything, it's the DPF that makes the biggest impact.