quick lil update. i ran the oem exhaust for a while and got the idle dialed back in. went back to the shop an had them double and tripple check it, rode it and all was consistent. then this weekend i slapped on the gpr with the db killer and "knock on wood" all is going well for the past couple days. idle is good, power is good. idle is staying around where it should and same as the oem pipe. so removing that db killer must remove way too much back pressure. which i have read of other cases where bikes ran crappy with that db killer baffle removed. glad i have some sound back. not as loud but a cleaner exhaust note.
i am thinking that when we initially adjusted it for the gpr w/out the db killer, it ended up way off and the ecu kept kicking in to correct but it was too much of a difference. which makes sense to me. so getting it all dialed back in with everything stock and then putting it back on, there was much less to compensate for, espaecially with the db killer in as that restricts the outlet to pretty much the same size as the oem outlet.
again "knock on wood" dont wanna jynx anything lol