Rattling noise after cold start/low speeds

Hey everyone,

I have seen previous threads on this (with no clear resolution) but mine sounds kind of different. I swapped out my stock OR exhaust for a pro exhaust last week. This morning is the first time I have noticed the sound

It sounds like a tin can ratting. It only happens after a cold start and for the first 5-20 mph, and it seems to go away after driving for more than a few minutes. It sounds like it’s coming from the cat area but not exactly sure. Any ideas on what this is? The video isn’t the greatest but you can hear it pretty well

https://youtu.be/B4mYj_bLFr8

 

Loose matrix in the cat, as it heats up it expands enough to quiet down.

 

Thank you- would this be fixed by tightening or is it something that I need the dealer to fix? Not exactly well versed on the mechanics of the cat.

 

Fixed by warranty, assuming that is what the problem is.

 

I have a strong feeling I’m going to get the “We couldn’t recreate the noise”... Really hoping they won’t waste my time. Would this mean the cat is busted?

 

I couldn't hear anything except for maybe some wind noise......

 

Yeah sorry not the best video took it on my lunch break. I could hear it well on the video playing it through my car bluetooth.

I found this video and it sounds similar but not as pronounced and doesn’t really happen when idling, has to be in gear and have slight throttle.

https://youtu.be/8_R8IMR24-k

 

Loose exhaust heat shield rattling?

 

Couldn’t find a loose spot, also wouldn’t explain why it only happens 5 through 15-20 mph then goes away above that/also why it only happens on cold start then goes away completely even at 5-15 after it’s warmed up.

 

Success, removed all exhaust/y pipe bolts and applied WD40 and locktite, retightened and the rattling was gone. Thanks for the help and suggestions everyone!