I really am having a hard time with my 98 a4 1.8t.....i thought for sometime that i wasnt running full throttle, but now that i took it somewhere people are telling me im not running full boost or no boost at all.....do you know anything else that i can check, that would make my car feel under powered? and do you know where i can get a good turbo at?

 

You can get a new or rebuilt K-03 turbo on ebay for $300.00>.

 

dont get a full turbo, but rather get turbo rebuilt kit, that way you will be sure thats all is good, on ebay cheap sometimes means crap.

 

I think you have a boost leak, check all the hoses, look for vacum leaks. the best way to do it is to pressure test sistem.

 

Could it just be my diverter valve not working at all? the turbo is spooling, becuase when i take off the bottom turbo hose, i can feel the turbo pushing a lot of air and it sounds great. Also the diverter valve is not pulling vacum at all. what do you think?

 

Its a possibility. To be sure try clamping off the pressure line going to the valve. If you get boost you have your boost leak.

 

i dont think that the valve is holding pressure at all. when it is off and the diverter vaLve is hooked up it almost goes back up to the 0 on the boost gauge, but when its not hooked up it will read -20 oin the vaceum. im going to start by buying A new valve