^then your car is not tuned for it you need a Cobb AP for your car to tune it for stage 2..i would suggest not driving it till you have done that or put back on stock downpipe
chances are the tool flashed it back to stock map before he gave it to the dealer and did not say anything so he could get a extra $450 out of hte deal by selling the AP
*edit jk..hurry up and get opensource if thats your plan then because right now your not tuned for that downpipe WHY has a subaru dealer not told you it has a non factory downpipe with a stock ECU and that could be the problem :S