Hi, mileage can affect the tuning of your system as the engine changes it's needs with wear. The trips taken with your trailer puts a demanding load on the bike that is safely handled by your upgrades, however more power = more wear on the engine itself, under load or not. I'd take it to a shop that has tuning software or back to your dealer and have them tune your bike, sounds like the popping is coming from the bike going lean on deceleration with the original ECM download you had performed on it. As always it cost $$$ to keep your bike running like a champ, so it may be worth looking into. As to go against add on packs, I'd just stick to actual ECM tuning and steer clear of add on packs that modify signals to the ECM for different calibrations. I'm not saying they don't work, as I have serviced bikes with them and even readjusted values to try to get better results. It's just the wrench in me that flinches at the idea of one more thing to troubleshoot when it comes to tuning. Good luck!
