I was doing some light reading earlier, and I read about a throttle body spacer for an xB.
Is there one for an xA? Is there any noticeable gains for having one? Is it even worth? I have a CAI, Header, Lightweight pulley so far.

Another question. Should I get a catback or axelback exhaust? I also read that doing just an axel back would be fine, with the stock mid section would be excellent. I would think the stock would hinder performance, to get a new exhaust from header all the way back.

thanks, forgive me if this has been answered before.

Also, do the xB axelback exhausts fit an xA?

no the xb exhaust will hang much lower. for exhaust mid pipe most that see decent gains do a custom cat back.