I’m running an ITR exhaust manifold, both the 4-2 & 2-1 section. I have this rattle going on that I cannot find. I Made sure all the little clips and stuff in the engine bay are not loose. I took of the intermediate shaft cover as well. The only thing that comes to my mind is the flex pipe on the 2-1 section. Inside the flex pipe section, there are these little rings that move up and down a little for flexibility. But I wonder if that vibrates when I’m giving 50% throttle. I look and look and look and everything seems to be nice and snug, which leads me to believe that it could possibly be the header. Anyone ever had this rattle issue with an ITR header before?