I bought a used 2006 Heritage Softail Classic; it has been popping on deceleration and in between shifting gears. It has a Vance and Hines slash cut big shot exhaust. I have been told from a mechanic that the baffles need to be pulled out and rebuilt to add more back pressure to remedy this situation. I had a local Harley dealer tell me the bike has an aftermarket air breather and a stock ECM. and I need to have a power commander installed and a dyno tune done because it's running too lean. What’s you're advice?