I just installed a high flow 200 CEL downpipe on my 2017 s all4 and I am getting weird codes. I expected codes, but none of them are related to 02 sensors as far as I can tell. I had no codes prior to this.

Engine-DME Digital Motor Electronics
CDA557 Signal (actual engine speed, wheel, 46.0.1) transmitter DSC Intermittent
CDA556 Signal (actual engine speed, wheel, 46.0.1) transmitter DSC Intermittent
CD944D Signal (actual engine speed, wheel, 46.0.1) invalid, transmitter DSC Intermittent
1F054D Drive, safety function: Wheel speed or acceleration implausible Intermittent
1B0A21 Information rough road detection, wheel speed sensors, signal: missing Intermittent
CDA558 Signal (actual engine speed, wheel, 46.0.1) transmitter DSC

ABS-DSC Dynamic Stability Control
4809CD Wheel speed sensor: Drive-off recognition, front right Intermittent
4809B9 Wheel speed sensor: Drive-off recognition, rear left Intermittent
48068C Transfer box: Temporary fault, temperature Intermittent
D356E6 Message (status, distribution, longitudinal moment, front axle rear axle, 19.3.4) not current, receiver DSC, transmitter VTG Intermittent
480686 Wheel speed sensor: Drive-off recognition, rear right Intermittent
D36D58 Signal (powertrain 1 wheel torque, 41.3.4) invalid, transmitter DME / DDE / EDME

I triple checked all connections and sensors and they all seem fine. The car drives fine, though there is a burning smell which I read might be related to the transfer box temperature fault.

It seems unlikely that 3 wheel speed sensors went bad from this install

 

https://bmwfault.codes/

I tried looking up a few of the codes… By chance, did you engage the drive while the car was in the air? If the car drives fine, I would be tempted to clear the codes and see if any come back.

The burning smell “could” be the down pipe burning off any manufacturing fluids.

Which down pipe did you go with? You last thread mentioned you planned on cutting the old one out. How did the install go?

 

As a matter of fact, I did engage drive and reverse while I had it up... I didn't realize that would throw codes. I was testing after the install to make sure there were no leaks.
When i was driving it yesterday, the CEL actually went off,. so I think we are all good The codes are still there, but I haven't driven enough to get them cleared. I'll only be concerned if CEL comes on again

I think you might be right, I didn't notice a burning smell after driving for awhile.

I went with the Evolution Racewerks 200 CEL high flow due to the 2 pieces it comes in for xDrive/all4 models. The install took awhile because of how much you have to take out to access the cat, and I wasn't familiar with it. The only thing I had to cut on the old cat to get it out was one of the hanger arms. The new cat went in nice due to the 2 sections.
However, I will say that the bracket used to mount to the engine did not fit very well. I ended up drilling new holes in the bracket to have it fit properly.


The second clamp was also a nightmare to get on once I had it clamped down to the turbo:

I also followed for the secondary O2 sensor and it hasn't thrown any codes. We'll see if it stays like that.

If I had to do it again, it would only take a few hours now that I know what I'm doing.

If anyone makes an xDrive/all4 downpipe, I would recommend using bolt-on hangers and having the downpipe one piece, instead of what Evolution Racewerks did. It would have saved lots of time during the install. But I am happy with the finished product. Next will be intake and intercooler before stage 2 tune.

 

Thanks for the follow on. Sounds like driving it will clear the codes. Motor on!