i have a '93 lude 2.2 vtec.

yesterday i installed 4-2-1 headers and a "high flow" cat. i got the old o2 sensor out of the old cat and put it in the new one. everything worked fine for a while and then my check engine light came on.

i turned off the car and turned it back on and the light went away so i ignored it. but now i'm randomly getting misfiring too. my friend with a 98 prelude had the same problem when he got his cat back done (with the after-cat o2 sensor).

is it just the o2 sensor that needs replacing?

 

See what code it is, either the o2 itself or the heater. Did you touch the sensors probe( part that sniffs the exhaust) with your fingers at all?

 

pfff. most likely. it was a bitch to get out. we were spraying it with liquid wrench and wd-40. and probably threw it on the ground once we actually got it out.

 

Lol, yeah dude, you're gonna need a new one. I just put in a new O2 sensor, and it had "Handle with care" and "fragile" and whatnot written all over it..

I got a Denos OEM replacement off ebay for $60 shipped, a lot cheaper than dealership. I bought it from this guy, super fast shipping ->
http://cgi.ebay.com/ebaymotors...photo

 

it's just weird cause i would think if it was busted completely then my check engine light would stay on, ya know?

 

I didn't even have a CEL, but I replaced mine and my car runs a LOT better!