So i got non resonated test pipes put in. And at like 3k rpms ive noticed rattle/buzzing noise

It hard to tell on a video but easily heard in real.
Here is a vid:
Anyone knows why?

 

That my friend is called rasp lol. It's a common thing with testpipes, and in order to make them work you need a good catback exhaust. I have the same issue on my sedan.

 

ye but its more like a buzzing, you dont hear it when you rev the car only when its being driven. Sounds like something is vibrating

On the outside you really dont hear it.
Here are 2 short clips of my car with the pipes on

 

check the heat shields

 

yep its probably your passenger side test pipe rattling against the passenger foot heatshield. mine did it from 2-3k till I stuffed motorcycle silencer packing between the pipe and heat shield. or you can remove the heatshield

 

interesting alright i will look into that too thanks for the info.

 

Here are two more short clips to describe the sound it sounds like it coming from behind..

 

Like everyone said, check the heatshields. I used to get a shaking noise also, found out one of the gaskets were badly messed up, slapped on a new one + sealant and exhaust sounded brand new!

oh and it's jenxin - Billy from ChicagoZ!

 

Hey! nice to see you on here, i got new gaskets from test pipe to y pipe and reused the original copper gasket i thinkm test pipe to headers