my friend thinks that i should get it welded?

 

to both ends? the header & the catback??

Definitely not a smart idea

 

I have had that rattle since day 1. Don't know where its from and have all new exhaust parts. Gonna have shop rev it when on a lift or something.

 

Sounds like the traditional exhaust noise to me, just amplified by the test pipes. Someone else had a comparible setup a little while back and they were complaining of the same issue. It turned out to be a pipe on the magnaflow catback shaking when reving and letting off. Never found out if there was a solution to fixing it or not.

 

lol..that rattle is completely normal, its the flex pipes shaking rapidly....no sissues, jsut noises you cant get rid of!!

 

would a different set up solve my problem?

 

Would he still have this rattle without the test pipes?

 

most VQs incl. G35 and 350z (so far all VQs I have heard) have this. even stock setup has this noise.
Depending on an exhaust, mostly HFC or testpipie, this noise is amplified.
You shouldn't hear this much while normally driving with stock setup though. Only when revving at neutral.

I kinda like it. LOL