You don't need to buy anything to leave the exhaust valve open and make a lot of noise, and you don't need any mechanical knowledge either!
Open the bonnet, start the engine, switch to "N" mode, open the fuse box, remove the fuse shown in the picture:
No risk, this fuse only supplies the exhaust valve, no error on the dashboard etc...
Moreover it is clearly indicated in the owner's manual (where I took the pictures above) page 9-54 and 9-57.
When you get tired of making a racket, put the fuse back in and everything goes back to normal.