So I have a 12 x sedan, and I have HFC's and a Tanabe Axleback on the car, it has had a rattle for a while but now that it is getting a bit warmer it's much more noticeable.

It does not happen while revving in park or neutral, only under load, comes and goes too and really is dependent on how hard you get on it. It does not seem to hinder performance at all.

Has anyone had to remove or do anything the Y or Mid pipe as far as heat shields go? Is there any specific place that anyone knows of that could be causing this? It's not where the Axleback attaches to the midpipe and it does not seem to be coming from the cats. Could it be coming from the thin tinny heat shields above the mufflers? I flick it and it sounds like it could be similar....

Just getting pretty frustrated cause it is so hard to track down!

I have searched the web far and wide already and I just can't seem to find anything that matches my issue or I am really bad at searching.

I tried to get audio but turned out crap.

 

my mechanic took my muffler off thinking someone stuck something inside my exhaust. he shook it while holding it up in the air and he said its the muffler itself that has become loose on the inside. i hear it the most on cold morning start ups. i also hear it when i close the doors or slam the trunk shut. it does a slight rattle.