Tsquarehair

So I just put on new IC’s for my b5 s4. (Slightly bigger than factory) all was fine an well...for about 20 minutes. Was boosting up to 15lbs like usual. And all of a sudden the car jerked, all boost dumped, abs light came on. Almost as if I blew a boost hose. I came to a stop and my rpm at idle was all over the place. After moving again The car jerked back and forth as if it was going in and out of gear but eventually stopped. Abs light went off and came back on every 30 seconds or so. Any ideas???????