I have a 2002 5.4 that I put a used Vortech on and now it doesn't seem to be up to par. I just got my boost gauge and got it installed. I'm only getting maybe 1-2lb of boost at WOT.

-All blades on the impeller are fine, nothing bent or broken.
-The upper pulley is the stock size, lower pulley is correct stock size.
-The belt and belt tensioner are in good shape. Doesn't appear to be slipping.
-Engine is basically stock except for Edelbrock throttle body, Dynatech headers, 3" single magnaflow exhaust, 42lb injectors. No aftermarket heads, etc.
-Boost bypass valve seems to be working. I have even disconnected it totally and still no boost.

What do I check next? I don't think my boost gauge is broken, because the truck just doesn't seem to have the power I expected. Sure doesn't feel like 6-8lbs of boost. I'm thinking the gauge may be correct. Would I not be getting any boost because of the exhaust modifications? How much will that drop boost? I remember on my 7.3L diesel, when I added exhaust, I lost a lot of boost. Is that the reason I'm not getting any PSI?

 

is that plastic tube kinked? its really easy to do, every thing tight not hand tight either i had a couple different trucks leak.

 

Finally figured out it's in my gauge.....bought a vacuum gauge and it has PSI on it as well. Hooked it up and right at 6 psi max. Guess I gota send my gauge back or buy a new one. First I am going to check and make sure the hose isn't kinked. I can''t see one but maybe behind the gauge pod.