Okay so I bought this 350z 6 speed and two days after owning it, it makes a weird clunking sound when idling it's not clunking after clunking it's almost like when I rev it at like 3k RPM when it comes down it makes a clunking sound it does have headers and strait piped to a nameless exhaust? That's what he told me IDK what it is but it's not normal please help!