2014 4 cylinder reg cab exhaust noise (?)

Greetings
I've had two 2014, 4 cylinder, reg cab 4x4's that have emitted a peculiar noise that seems to be coming from the exhaust/catalytic area just behind the cab.
It occurs at hiway speeds when I lift from accelerator, sorta sounds like a rattling of a can o coffee beans, or dominoes, I think it's exhaust related anyway, from compression? or I guess it could be drive shaft. Always forget to ask at dealerships, had one service guy ride along in my 1st one years ago, I know he heard what I was talking about, but played dum... anybody have a better idea ?
Many thanks for any response.

 

Likely a heat shield that's bent or loose.

I had one that a mounting bolt was cross threaded and did not draw up shield tight. Can you say somebody's been here before!

Was hard to access, could not remove or tighten. Used a block of 2x4 and a hammer to massage shield. It's still loose, but not rattling anymore.