So, was out ridding, and my bike makes an annoying rattle. After some worrying and a foot on the pipe, it's the pipe rattling at it's resonance frequency. Not really and issue, but a annoying. Anyway, any easy fixes?
I have found that 43x3.5 o-rings seal better. However, the pipe is much harder to install.
The trick is put the o-rings in the groove dry, then grease the outside of the o-ring and the inside of the pipe flange. Slide the pipe on as far as you can by hand. Then install the springs to do the final pull.