I've heard alot of good things about Omar. You should be in good hands.

One thing to ask. In some cases, to turn off the CEL, the tuners leave the O2 sensor in a not fully ready state to avoid the cat efficiency below threshold code. If you state does their emissions testing based on OBDII, you may fail due to a failed OBDII readiness test.

There are ways around this. For other vehicles, there are true O2 emulators that will mimic the signal of the O2 sensor. You can also drill out sparkplug antifoulers and try varying spacers to fool the computer to thinking that it is seeing the data is wants. (You can measure the volts on the O2 sensor and see what brings you closest to .45v. O2 sensors will read from .1v to.9v, .45v is about 14.7-1 air/fuel ratio.) You may need to play with the O2 sensors before and after where the cat was to get a similar reading. I would be willing to bet that if they are far our of range of each other, you will get a code.

My experience is with older DSM cars, mitsubishi starions, some subarus, and mustangs. I have very little BMW specific knowledge. I am learning.

Omar will definitely know better. You want to make sure that you clear the CEL in a way that allows you to pass emissions. Taking out the DP's is only a 3-4 hr job, so it is not unreasonable to do it each year for emissions.

Also, before you order. Be aware that at some point, BMW changed from a flanged connection on the DP (shown in your picture above) to a slip fit connector. Be sure to go under the truck and confirm what type you have before ordering.