My 2003 Road King seems to have reduced exhaust pressure on the back pot and it has developed popping on throttle close. Checked for leaks and plugs are new and set correctly just wandering if there could be a coil problem developing .... any ideas.

 

could be deposit build up around valve seats I run some good STP fuel treatment every now and then made for motorcycles helps clean the deposits and maybe even save a burn valve AMSOIL redline Lucas Oil all make very good products for cleaning deposits up around the fuel system