F30 n20 fuel pump failing?

[Troylee9]

Sorry to start a new thread but i am new to the forums and havent seen anything as direct as my issue. I believe my fuel pump is failing because lately when i try to start my car it struggles to turn over or turns on and quickly turns off. I first noticed that when i set my jb4 to map 2 it felt as if the rpms were not keeping up with acceleration or if my transmission was slipping so i set it back to map 1 to be careful. it seemed the issue only became not as bad. I am planning to go to bootmod3 and thought possibly that could be the problem because i heard bootmod3 was “smoother” than the jb4. I never had that problem on map 1 until i went map 2 and then back. I have a aftermarket warranty through BMW but with the catless downpipe i do not want them to void my warranty or say that is the issue. I have a “mod friendly” mechanic but he doesnt seem to really take his time with my car (i know its not the center of the universe but to me it is my baby). Any idea of what it could be? Should i pay the $150 to put my stock dp back in and disconnect my jb4 and take it to bmw? As of now the only cel is the dp.

[MauiM3Mania]

Moved discussion to the model specific sub-forum.