after installing my injen cai i always hear like metal shaking against another metal. im thinking its the heatshield am i right? and how can i fix this?

 

I had this problem a while back ago. Your heat shield is vibrating against a metal line. All I did was made sure that the shield was torqued down and adjusted for clearance. You may have to readjust it just a tad bit.

 

We took a power grinder and grinded the part so it fit perfectly. Or you can take a pair of pliers (angled) and bend it out. Both ways work we used the first on the white one, and the second on the brick, b/c it was already installed.