[green grass]

If you're reading this, you probably know what's going on.

The Problem

The exhaust flap has a range of motion of 90 degrees (obviously - full open to full closed). It rotates from 45 degrees to 135 degrees.

However, the actuator has a range of motion around 130 degrees or so. Open is around 25 degrees, closed is around 155 degrees. This is so that the actuator twists more than the valve putting tension on the clip / fixing bow it in both the open and closed position. That keeps the clip / fixing bow from rattling or falling out.

The downside of this is that if you align the slots on the flap and the actuator, the actuator is mis-aligned with the holes to bolt it in. If you align the actuator with the holes, the slots are mis-aligned.

I fiddled with it for half an hour and the fixing bow kept popping out.

A solution

1. Remove the three bolts holding in the actuator
2. Unclip the actuator from the wiring harness
3. Push the harness back into the actuator almost all the way, but not enough to engage the clip
4. Practice popping the actuator off the harness quickly with one hand
5. Plug in your OBD device, turn the ignition on only, and connect via BimmerLink or similar
6. Use BimmerLink to open and close the actuator a few times to make sure the harness is connected and get a feel for how fast it moves (half a second or so?)
7. Using one hand, open (or close) the actuator with BimmerLink. It doesn't matter which, so long as it moves. Using the other hand, pop the harness off
8. The actuator should be stopped mid-stroke. Mine stopped at the 90/3 o' clock position
9. Shut the car off
10. Now you can line up the fixing bow, the actuator, and the bolts with no twist in the bow, and simply bolt the assembly together with no twisting tension.
11. Plug the harness back in, making sure it actually clips this time.
12. Turn the car back on, cycle the valve a few times with BimmerLink to make sure it was done right

If done right, the actuator will look like this, which is so much easier to deal with: