Ok so the previous owner installed a MBC and I tried to take a look at it and see if I could reverse it back to the N75 and here is where things got a bit confusing: what I found in my car was the MBC was connected to the wastegate with one nip, to the N75 with the second nip and then the third was the bleeding. And the N75 was connected to the intake before the turbo before the turbo on one side, the intake after the turbo with the lower nip, and the other side to the MBC. Is there any reason why they installed the MBC this way or it was just a sloppy job? And in order to reverse it should I just connect the wastegate back to the N75 side nip?

Thanks!

 

Did it look at all like the picture here?:
No title

 

Nope. It looked like this (Im not good at drawing I know)

 

the way that boost controller is hooked up is wrong. with the way it is set up it will probably overboost. just hook up the wastegate line to the n75. if it is a 3 port mbc, and it is bleeding pressure, the wastgate diaphram wont see the proper amount of pressure and it won't open

 

The weird thing is I was underboosting, never got over 5-6 psi!

Anyway I hooked the wastegate back to the N75 I'll take it for a drive today and see what happens...

 

Ok so now after hooking the wastegate back to the N75 the boost doesn't work AT ALL!
So maybe the MBC was set up in that weird way because the N75 is not working?
Or is it possibly something else?

Update: I checked the connector to the N75 and the yellow wire is disconnected. I guess this could explain the code and the lack of boost right?

 

What do you mean by the boost isn't working at all? 0psi?

 

Yep. The boost gauge won't move at all and I can feel the car is noticeably slower. I'll try reattaching the yellow wire to the N75 plug, I hope that's gonna fix it.

 

Then I'd look at the wastegate. And make sure the lines for the n75 are on the correct nipples

 

I'm pretty sure the lines are correct now, the bottom nip is on the rubber air intake before the turbo, one side is connected after the turbo and the other side I connected to the wastegate. I didn't unplug them all, but the nipple I connected to the wastegate didn't look like the long one so it should all be correct. I might wanna try to shorten the rubber hose to the wastegate though, it's pretty long and it has a junction with another slightly larger rubber hose to fit in the N75 nip.