How many miles on your JK and what year? If it's under 8 years/80k miles it's covered under federal warranty. Mines been rattling since about 80k miles, currently at 115k miles, code came up about 2k miles ago. Jeep is a 2010. I'm SOL and going to wait until I need to smog. If I didn't live in California I'd be going with Ripp headers.
First, take a 50/50 water/alcohol solution and douche all the sand out of your vagina. Seriously, you gotta get that nozzle ALL the way to the cervix since it sounds as though your vajayjay is completely blocked with a silica compound.