Quote:
Originally Posted by bobbis1
Spacers serve to move the 02 sensor away from the exhaust path so the post cat exhaust doesn’t not appear to be running so rich to the ecu.
I ran these with no issue with a set of sport/race cats on a car w finicky emissions system.
http://www.bigdaddiesgarage.com/straight-cel-fix.html
My 355 has the cats removed so I run these
https://www.fabspeed.com/universal-9...SABEgJGBvD_BwE
Which actually put a fake cat ahead of the sensor
One thing to be wary of (Someone more familiar w modern bmw engine management will have to chime in) I have read that certain cars actually make use of post cat 02 readings to adjust fuel trim in the engine. Doesn’t make a ton of sense to me that a car should do this but maybe poke around the f90 forums rather than being a guinea pig on a 125k$ car  . |
Bobbis, thank you for the link to the quality spacers. For $30, I grabbed a pair. Can't hurt to try. I'll let you know how it goes. I hope there's space for the install. It's gonna be a pita removing all the under sheathing to be able to access that area.