Ok i have apr v.2 and a j-valve and was boosting like 18-20 psi no problem all day long. I just recently got a downpipe 3in with a test pipe and had it installed and took out the resonator. When i got the car it felt a lil stronger but not much then my other vw friends that night told me that my car was smoking alot and blowing out black smoke and running rich. So i let another friend drive it and he was like the car isnt that much faster it feels kinda the same. I was hitting 20-21 psi so the next day i went to the other local vw hang out and someone asked me if i wanted my car vagged and i said sure why not... i threw two codes 1. boost pressure exceeded 2. Cam timing retarded. I had the codes reset and the did a throttle body alignment with the vag-com and ever since then my car won't boost more then 16 psi even with a 3in downpipe and test pipe along wiht a j-valve.i dont' know what to do or waht to look for does anyone have any suggestions?????