With the stock pipes, the exhaust was fine but was too quiet. I had HD shop put on stage one kit with Vance & Hines pipes. I immediately got excessive backfiring and popping, even while changing gears. If I let it back down in any gear, it sounded like a 4th of July celebration. In addition, the engine ran so hot, I felt like a pig on a spit. HD immediately said it must be the V & H pipes, so I had them change to Screamin Eagles. No difference in popping or temperature. They fiddled around with downloads, but got no positive results. They threw up their hands and said they were getting a new computer in a month or so that may enable them to do a better mapping for the FI. I then took bike to a local shop who sells a lot of Power Commanders. He installed a PC and this seems to have reduced the backfiring by 75 - 80%. It seldom backfires anymore when changing gears, but will do so when backing down in gear and you reach low RPMs. The engine does not seem as hot anymore, so I imagine it is not running as lean as it once did. Although the situation has improved, I am still not entirely pleased with the result. Now, the HD shop calls and tells me that for $700 they can install a race tuner that will solve the "popping" problem. Since I already paid $600 for a PC and a Dyno tuning, I am not in the mood to spend another $700 for something that probably will not make the problem go totally away anyway. Has anybody else had this backfiring problem after putting in a stage 1 kit and pipes? Would appreciate any input. Thanks, Fred Burcaw