okay, I could not find an information here about the diameter size of the stock catalytic converter. anyone can guide me to some links? or anyone has idea?
5th gen SH.

 

I found a thread but still not making sense. lot says 2" and some says 2.5".

one thread saying that cat diameter is 2" since exhaust pipe is 2"
https://honda-tech.com/zerothread?id=828555

one thread saying that from 4th was 2" and 5th gen is 2.5". So Im assuming that on the second thread since 5th gen has 2.5" exhaust piping the cat should be same diameter.
https://honda-tech.com/zerothread?id=1206270

which is one true?

 

im sure its not 2.5, 2.0 sounds right

 

actually the 97-01 prelude has a 2.25" exhaust

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tacticalcustoms &raquo;</TD></TR><TR><TD CLASS="quote">actually the 97-01 prelude has a 2.25" exhaust</TD></TR></TABLE>

If 97-01 has 2.25" stock exhaust, then cat diamter is should be same right?