So I recently pulled my motor in my 2007 WRX due to the timing belt tensioner bolt snapping off. I got the motor back in the car and noticed a new noise it’s sorta like a rattling sound but i can’t really describe it. I’ve climbed under the car and it sounds like it’s near the up pipe but I’ve double checked all the bolts and everything is tight. It has a new IAG header and Up pipe. The noise gets quieter when you go above idle but as soon as you let off the gas it gets quite loud.