Hi guys. So i recently installed a K04 and upgraded to the APR K04 software. On the way home I was experiencing a Goose Honk from my APR R1 diverter valve at full boost, half throttle. So i reversed the orientation of the DV and the Honk went away but then i started experiencing boost surge (boost jumping up and down) at 3000 to 4000 RPM at full boost. so immediately i thought it was because of the reverse orientation of the diverter valve. i took out the APR R1 and installed a Forge 007P with a yellow spring today and the boost surge is still there.

I called the shop that flashed my k04 tune and they said to replace the n75 valve and see if that alleviates the problem.

If that does not fix the boost surge, what else can it be?

Does anyone have a solution for this?

I read some other threads and some say to run a mbc parallel to the n75 and this may help.

Any thoughts?