Another update... the ecu has not been replaced...
I’ve been wrapping my mind around selling the car because the issue was driving me crazy, so I decided to start putting oem parts back little by little. 2 weeks ago I decided to replace the grimmspeed ebcs, making way to go back to the TD04 afterwards. Since then, there have been no more stalls, or the “hiccups” it gave at idle.
I did get one hiccup at a red light a week after replacing the ebcs, where the revs dipped a little, but not to zero, the engine didn’t stall and the CEL didn’t flash. The car ran a bit rough at idle, and seemed like it wasn’t controlling idle revs. When I checked my ebcs connections, the T hose on the compressor side had a bit of a rip, and to make matters worse, the coolant hose right on top of it was leaking a bit over that hose. Made a new piece of hose, swapped the boost pill to it and repaired the leak on the coolant hose, so now idle behaves normally.
It’s only been 2 weeks since the ebcs was replaced and no more stalls, but this issue has fooled me before, so I’m still vigilant and my hopes are not completely up yet.
I had never thought of replacing the ebcs because I never saw the stall as a boost cut. I still have to do some more testing to be completely sure. I’ll update accordingly.