will the full catback exhaust from the 99 si fit on a 99 civic hx?

 

looks like no:

the top exhaust is for the HX-notice that the HX has the cat built into the upper part of the exhaust manifold,so the exhaust is longer from the resonator to where it meets the downpipe.
BUT,the Si exhaust will fit if:
1) you also get the Si cat.this will make it the proper length.
2)you get the midpipe cut and lengthened between the resonator and flange.
3)you make a test pipe to fit where the Si cat should go.
....anyway,it will bolt right on if you have the Si cat too,but i'm not sure how much it will hurt performance having the restriction of two cats on it.i guess you could always gut the Si cat and just use the shell.
Chris

 

does it change anything if i have the ex headers an no cAT

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sohcturbo16 &raquo;</TD></TR><TR><TD CLASS="quote">does it change anything if i have the ex headers an no cAT</TD></TR></TABLE>
if you have the EX mani you will need the EX cat or a test pipe to bridge the gap to the midpipe.
or,your stock HX exhaust should bolt right to the EX mani.
Chris

 

yeah the only main difference is the cat location

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sohcturbo16 &raquo;</TD></TR><TR><TD CLASS="quote">does it change anything if i have the ex headers an no cAT</TD></TR></TABLE>

what about the 02 sensor?

 

yes it will fit.