I also want to get the VRSF 4.5" CATLESS DOWNPIPE B58 from Extreme Powerhouse.
I'm holding back on my purchase mainly because of the CEL light, and I don't want my SA to write it up when I go in for service.
I don't like the current solutions - JB4 or Flash tune (expensive just to remove the CEL light).
I found a post from f30 bimmerpost, and he had success with the 90 degree o2 sensor extension. Here is the link:
https://f30.bimmerpost.com/forums/sh....php?t=1428608
Did anyone try this with their M240i?