Hello all- Im new to BimmerForums but felt the need to post this. A few weeks ago I was getting on to the highway and floored the accelerator. As I gassed it the car went into limp mode and the EML, DSC and brake light went on. There was no check engine light. I pulled to the side of the road and restarted the car and it drove without issue. I stopped at the gas station, filled it up tightened the gas cap and drove home. Although I didn't put it all together (flooring the accelerator) the next day the car went into limp mode again with the same lights. Pulled to the side of the road and restarted. I was now able to recreate the problem each time I floored it. When I went to read the ODB codes I found nothing stored but two pending codes:

P1638-Throttle Valve Position Control -Throttle Stuck Temporarily
P1639- Throttle Valve Position Control -Throttle Stuck Permanently

After reading a bunch of forum posts, it seemed that the problem was intake/ fuel system related but could have been a number of different things. I decided to begin by cleaning the throttle body. After an hour plus of trying to figure out how to remove the TB I finally pulled it and began cleaning with CRC throttle body cleaner. There was a bunch of carbon build up in the TB but also another surprise, a black flap was stuck in the intake side of the TB housing. Just figured out what it was...the flap from the DISA.

The DISA was supposedly replaced last year however mine didn't seem even fairly new (BS shop). This must have happened during another DISA replacement. This probably also accounted for a noise that I thought was the VANOS rattle (marbles in a can). Put it all back together and the car runs the best it ever has. I just hope this saves someone else aggravation.