Originally Posted by
93DituneEX
where does the o2 bung go on a 2000 Civic EX?
See if this
PHOTO is detailed enough for you.... FYI, #28 and #41 are the O2 sensors and #4 is the cat. You can see #41 goes in at the end of the stock A-pipe and #28 goes into the back side of the cat.
Originally Posted by
93DituneEX
I was just told that one goes before and one goes after....but where after the cat? Does it matter?
Yes it DOES matter. The OBDII ECU requires a O2 sensor before and after the cat to measure catylist efficiency. You'll get the dreaded P0420 if you don't put them in the right place.