Not the heatshield its secure, all clamps are tight and secure, filter has been freshly recharged. there is a high pitch rattle at 1800 rpms through every shift. If ur traveling slow like me, sometimes you'll stay in that rpm range for a good lil while, and its so loud that other traffic can here it. Theres no way that its the normal breathing sound from the filter. Almost sounds like a Heatshield to be honest. Also this only happens while driving, if in park and reved it won't do it at all. any ideas?