Hubby has an 2007 1200 sportster with V&H Short shots, stage 1 K&N breather. The bike is popping sometimes. We've been trying to do research on what to do next with it. It has been downloaded. Now our issue is our conversion on fuel pack, tuner or power commander. What is the difference, what would be more bang for his buck?? We were also wondering what the difference is between download, mapping and being dyno'd?? We've had many techies use those phrases. Are they something different or is each one different??