[Micke_B]

Ok, I tried looking around for this but I could not find an answer. In the EU we have these lovely OPF / GPF filters after the cats. And between the cats and the filters, there is a sensor(s) (one per pipe I guess) that measures back-pressure in order to figure out if the filter is there (is working) or not.

Fine, I thought. That is ok, I do not plan to tune my car but I do want to change the fugly exhaust. Both for some more sound and for some less provocative looks. So I'll just install an OPF / GPF back exhaust.

BUT if I put on an OPF / GPF back exhaust the back-pressure behind the filters might, most likely will in my case, drop/change. And that little sensor(s) will interpret that as the filters are missing or broken = limp mode?

The only solution I found is the
"AK-Motion Data Display BMW M2 (F8x) (Competition / CS)" that manhart sells.
https://www.manhart-performance.de/s...ion-/-cs?c=261

But seems like all it does, OPF / GPF wise, is to hook into the sensor cables and adjust the value a little? So that shouldn't be too hard?

Is there any other way of doing this? Does some other sensor disable device that only does that?

[kart driver]

Originally Posted by Micke_B

Fine, I thought. That is ok, I do not plan to tune my car but I do want to change the fugly exhaust. Both for some more sound and for some less provocative looks. So I'll just install an OPF / GPF back exhaust.

BUT if I put on an OPF / GPF back exhaust the back-pressure behind the filters might, most likely will in my case, drop/change. And that little sensor(s) will interpret that as the filters are missing or broken = limp mode?

As I’ve read some exhausts, slip on systems, like Akrapovic and Remus will not cause any CEL.

[NathObeaN]

Originally Posted by kart driver

As I’ve read some exhausts, slip on systems, like Akrapovic and Remus will not cause any CEL.

Correct. You have a few options - Homologated which are guaranteed not got cause problems. Slip-on exhausts that are not homologated but for the most part do not cause CEL (check with manufacturer) and slip-on + resonator delete (optional, depending what country you are from this may or may not be acceptable). This also does not appear to cause CEL, check with manufacturer and garage though.

If you remove the OPF, you'll need an ECU remap or something that can manipulate the sensors otherwise you'll get CEL. It's also technically illegal in most places.

[Micke_B]

Yeah I do not want to remove the OPF or tune the car. Just want a little more sound and to get rid of that ugly rear box. So EC approved slip-on then. Hmm.

[Detoxified]

Originally Posted by Micke_B

Yeah I do not want to remove the OPF or tune the car. Just want a little more sound and to get rid of that ugly rear box. So EC approved slip-on then. Hmm.

You could install the AK-Motion display as you mentioned. This does not "tune" the car. It is simply a piggy back on your CAN-Bus to read values and display them on the screen. It does some minor coding, not tuning for various things like exhaust flaps or in your case OPF-Delete. I installed this display on my 2020 M2C since I want to use it's delete-R feature to remove the CEL when I put a downpipe on, without tuning the car. This is so I can maintain my warranty. Let me know if you have any questions regardin the AK-Motion display, I love mine.

[Killed by Death]

Don't do it if you have a White M2. My old MC4 got dirty as FUCK without them.

[Micke_B]

Originally Posted by Detoxified

You could install the AK-Motion display as you mentioned. This does not "tune" the car. It is simply a piggy back on your CAN-Bus to read values and display them on the screen. It does some minor coding, not tuning for various things like exhaust flaps or in your case OPF-Delete. I installed this display on my 2020 M2C since I want to use it's delete-R feature to remove the CEL when I put a downpipe on, without tuning the car. This is so I can maintain my warranty. Let me know if you have any questions regardin the AK-Motion display, I love mine.

Thanks. I'll see what I'll end up doing. Just discovered that the stone exhaust cat back won't trigger the sensor at all. That would be ideal.