I got a third hand sr2 800. First owner did all the mods like tail chop, belt cover removal....and open pipes. The lack mufflers is incredibly loud and awe inspiring, and looks bad ass. However, it lugs at low revs and backfires under hard down shifts, which makes it not so bad ass. Second owner claimed the Ecu was for the open pipes, but he screwed me on a couple of mechanical issues, so I have think he is full of s*%t. Any advice to fix this before I suck it up and go back to a full exhaust system? I saw a few other threads about open pipes that did not have this issue.