I'm testing this for you as we speak.
So I had the `little cough problem` since +- 10 days. Especially when the engine is cold, around 1800 - 2000 rpm, and pushing the pedal just a few mm down. Resulting in the boostpressure to drop to zero. When giving a little more gas, there is a delay followed by a hikkup, afterwards things are normal again.
I had no issues starting though. What I did see was a 13% milage increasement over these days. I keep track of my fuelings: https://www.spritmonitor.de/en/detail/746178.html
First I thought it had something to do with my new tires (the milage increasement), but I couldn't ignore those `coughs`, so it had to be EGR related.
I've ordered the EGR simulator/cheater from ebay, and it's still on its way. However I couldn't stand my car being suffocated while waiting for the device. So I made my own EGR blanking plate out of 4mm RVS and as predicted after three runs the engine light came on. I've driven 200KM so far. No noticable power inprovement, but hey, I just had the problem for 10 days so thats different than having the problem for over a year.
The milages did improve and it's back to normal I guess, maybe a little better than normal. Atleast thats what the ECU is telling me, and it has proven to be quite accurate over time. I know for sure in 3 days when my tank is empty again.
I will leave the blanking plate on until next weekend, then i'm going to add the EGR simulator/cheater and see if that makes any difference in milage or power.