Since a couple of days my FD is making lower boost on the second turbo but only in 4th and 5th gear.

normal boost level is 0.78 bar with the mods I have on both first and second turbo but now the second one is only at 0.2 bar max in 4th and 5 th gear.

I was wondering if someone had this as well? I'm converting to non seq soon but it would be nice to have it fixed for the time being.

I guess it's not a vac line leak because then it should be in all gears...

 

Vac line leaks can cause erratic symptoms. I still think that's the place to start looking. I would first check the line leading to the charge relief valve, and the lines leading to the turbo control actuator.

 

Thanks, I will check that