Well I recently put a boost gauge on my 98 a4 1.8t with 108k miles, and it surprised me to see that I'm, at max boost, only pushing 2 psi. I replaced the diverter valve, but I don't know whats wrong. Any suggestions?

 

there are three quick and easy vaccuum sized lines that can easily be checked in the intake manifold, my boost leak went from the diverter valve to the n75.

 

and how did you fix your boost leak? tighten clamp? replace hose?

 

Make sure your hose from the intake manifold to the DV doesn't have any cracks in it. Otherwise it's in limp mode.

 

The hose from the dv to the manifold was just replaced and I'm still not boosting over 2 psi. which hoses should i check?

 

I have a similar problem but am maxing at 5 PSI. this was an intermittent issue, but for about the last week has been a constant. I have the N75 "race valve" installed and was thinking that might be the issue, any other suspects. maybe my thinking was wrong, but i thought the intermittent aspects of the problem ruled out something like a vacuum leak.