Vibrate & bass sound

[Legend@wheels]

Hi
Before Few months ago i replaced my first catalyst convert + manifold( it was broken) cuz it made bass sound and vibrates at 3rpm-4rpm-+ ,now it got back but the catalyst is new and un broken .
Is anyone familiar with this problem?
Tbh the sound is kinda cool but it surely feel like something is messed up

 

[Chris]

Baffles gone in silencer perhaps.

or a slightly blowing exhaust perhaps.

 

[montana]

Do you still have your centre silencer ? Check that and the heatshields around the full length of the exhaust. Also give the exhaust a gentle tab around any silencers (mid and backbox) and check for any signs that the baffles have gone (loose metal sound)

 

[Legend@wheels]

The car has only 56k km how come so many faults with the exhaust ,wow it realy messed up!
The exhaust is not suppose to even tweet under 150k