[marmit2017]

So I've had this rattle that sounds exactly like this.

It's such an easy fix and so cheap. If you want to maintain OEM functions so that the exhaust opens and closes this is the part number for the spring/clip. 18307620323. The sole reason for the flap is for sound. It's supposed to open when you accelerate or press the accelerator and stay closed when idling for quieter sounds. I however went the cheaper and "better" route. Just got a wire and tied it around the flap and exhaust so it stayed open all the time and in place, not moving, hence no more rattle. The spring would go in between that flap "knob" and the motor to the left. If you go the wire route just make sure before you secure it with wire that the flap is in the open position, you can tell by simply looking down the exhaust with a flash light. This is the same for all F30 models. Only thing different is the models with two exhaust just has two flaps/actuators.

[F30xi]

By any chance did you unplug the censor or keep it plugged in?