Sand shifting noise under seat when turning

So, I recently bought a Mitsubishi Lancer Evolution, 2008. It’s a great motor and is mint. However, every time I turn, there seems to be something shifting around under the passenger side bucket seat. The only way I can describe it is sandbags being tossed around.

Any help?

Remove the seat, and then drive the vehicle while someone in the back seat observes what happens.


Tap the cataylitic converter with a rubber mallet and see if you get a similar sound.

I think I found it. They seem to be tiny grey plastic balls. Any knowledge where the came from?

This is a pic with a 5p coin for scale.

Hey there. Turns out it was a load of those tiny plastic or metal ball bearings under the carpet. Luckily there were a few slots in the carpet here and there and managed to get my vacuum down there and pick it all up.

Now it is silent when I turn hard into a bend. It wasn’t the cat converter but you made me see how rusty it is and how it’s not going to pass the MOT.

Thank you very much!

They look like air gun pellets.