I just bought a 2003 z a few weeks ago. Love this car! But I do have a few (probably stupid) questions.....

The guy who had it before me has apparently put a bit of work into it. I got it on a lift the other day and noticed it has test pipes (car isn't throwing codes) and the resonator was deleted. It sounds VERY raspy (like Honda civic rice raspy).... I don't really want to put cats back in it because..... Well.... I'm cheap. I was curious if I put a resonator back on it if it would kill the rasp (i have a stock resonator and muffler sitting in my shop anyway).

Also, as I was poking around under the hood, I noticed a 1/2 metal divider between the upper and lower half of the intake plenum.... Is that a plenum spacer? Or is there a standard oem spacer that normally resides there anyway? I ask because I thought the aftermarket spacers come with shims to space the strut bar up too, but I dont see any under my strut brace...

Also, is there any easy way to tell if the ecu has been reflashed/upgraded?

 

That would be a plenum spacer, yes. I'm not sure about the ecu reflash but a resonator would probably kill the rasp, yes

 

If you have test pipes,adding the resonator back will not totally eliminate
the rasp.It will be quieter.Adding HFC's would further quiet it down.Some
Y pipes help with rasp.I'd put the resonator on and see how you like it.
Go from there.On the plenum spacer,if its a 5/16" spacer,it should not
need any shims.Maybe a washer...If its a 1/2",possibly a aftermarker strut
bar is on the car?Hard to say if your car has been reflashed.Unfortunately,
its common for many owners to mod their cars and not do the necessary
adjustments in the system to make it all work correctly.I see you live in TN.
Are you near Nashville?Crawford Z is a great shop.You may want to contact
them.

 

Ok thanks guys. So the resonator will help but not eliminate the rasp..... I don't get how a y pipe would help though... Are they resonated?