2001 Monaco Knight accelerator problem

[Mksa]

I have 2001 Monaco Knight with isb260-mc/99 serial# 46050572 and I'm having trouble with the  throttle losing response. When I turn off the key and restart it it runs fine. The problem is getting more frequent. I was told the issue could be in a APPS  but I am having trouble locating it.  Any help with the location and any other advice would be appreciated thanks Mark