yanbu

I posted a month or so back about buying a stage 3 s4. To make a long story short, I bought it, love the car, but last week it started not holding as much boost as it was.

According to my boost gauge, I was getting 20psi or so and now I am getting 15 or 16. If I really get on it it will max out around 18 and then go back down to 15 or so. I read up on the problem, and checked the TBB (no problems there) and in the process found a cracked vacume hose going to the driver's side DV, which I replaced but am still having the problem.

I am not driving it at the moment since I managed to get my truck running, but I need to get this fixed while I am on vacation and have time to work on it. Has anyone had the same problem or have any suggestions as to what all I should look at? F-hose maybe? Should I track down a pressure tester?

mbox

Definitely do a pressure test.

JasonS4+Festicle

When you got the car, was it 60 degrees outside and now 10F?

Just curious because temp changes can make a difference - not sure if that much of a difference though.

Do a pressure test and report back.

ImolaPR

I had the exact same issue and it turned out to be the N-75 valve.

yanbu

AWE kit

yanbu

Thanks for the input