* Loose bits of metal. Over time, the internal components of your catalytic converter can become loose and start to rattle around. This is most likely to happen if your converter is old or has been damaged.
* A broken baffle. The baffle is a metal plate that helps to direct exhaust gases through the converter. If the baffle breaks, it can cause the gases to flow turbulently, which can create a rattling sound.
* A damaged honeycomb structure. The honeycomb structure is made up of a series of small channels that allow exhaust gases to pass through. If the honeycomb structure is damaged, it can cause the gases to flow unevenly, which can create a rattling sound.
If you hear a rattling sound coming from your catalytic converter, it's important to have it checked out by a mechanic as soon as possible. A damaged converter can cause your vehicle to emit harmful pollutants and can also damage other components of your exhaust system.
