So i just got my b5 s4 out of the shop to fix a boost problem. Before taking it to the shop i could barely hit 5 psi and could only push the gas in about half way before getting an awful misfire sound. Turns out i had a blown cylinder but everything was taken care of and the car feels great. The car definitely is alot faster than before but it just doesnt quite seem the same as before i had any of these boost problems. I was usually at a steady 15 with spikes of 16-18 but now i am only getting to about 10 psi. Its more than before but i would like to get back to my original chipped boost psi. I was wondering if fixing the cylinder only partially fixed the problem and i have another boost leak lieing around somewhere?Any info would be greatly appreciated.

 

check your tbb.. that went bad on mine.. also the f hoses are know for going bad. otherwise look into a pressure tester.. i think awe sells one for pretty cheap.. it helped me locate an intake leak around a fuel injector o-ring on mine.. (of course i used a water spray)...

 

did you upgrade your diverter valves from the stock ones? if not you should probably do so.