2001 Jetta exhaust questions

[Tommy Gun]

Hey everyone. Sorry if there are already a million posts about this.
So my CEL came on 1 day after buying my car. It gave a P0420, saying something about banks are too lean and the cat should be replaced.

So I was just going to get a cattless downpipe with an 02 spacer for no CEL.
I was wondering if anyone have experience with this?
The main question would be if it will sound nice with a stock catback exhaust.
I am planning on getting a catback at sometime, but right now im just replacing the downpipe.
My last car was a 1998 mustang gt with a cattless midpipe and flowmaster exhaust, i do not want something this loud again

Any advice? Thanks

[Tommy Gun]

1.8T AWW motor by the way

[JUSTION337]

I have a 3" 42 Draft Designs catless downpipe and a Milltek 2.5" catback without a resonator and it's fairly quiet when idling and cruising until you put your foot into it,then it gets a bit louder.

[SlimMJS]

The turbo quiets down your exhaust a lot as compared to the NA mustang.