Anyone with an aftermarket exhaust have any issues with CELs?
I was at the dealership today to get a rattle fixed and to get the diff fluid changed. My SA is really cool and I mentioned I was considering an exhaust and he recommended against it, not because he thinks they cause problems, but he seemed to imply that people have had warranty issues. I also had a tech ride with me to figure out the noise and he claimed that all any change to the backpressure is known to cause CELs in the M3s and that he wouldn't do it. Again, he wasn't talking about actual issues or warranty claims, just that in his experience the car will think something is wrong even if it's not.
I can see CELs if the whole exhaust is changed, but I haven't heard anything like this in the past and from my readings here am pretty confident that just an exhaust (not messing with smog components) won't be an issue.
Has anyone heard anything similar from a dealership or experienced any issues with their exhaust (CELs or warranty issues)?