2006 Heritage, heavy duty oil pump, SE204 cam, stage 1 and screaming eagle pipes. Bike has always run great until last summer when it started stalling out when down shifting into first and occasionally it will surge when you pull in the clutch. Harley said it was dirty fuel injectors so we replaced them ($700+) and we use injector cleaner in every tank. And it still does it. Going down the road it's great. Any experience or ideas?