Hondata

I'm just wondering why an 05-06 O2 sensor can't be used. What's wrong with it exactly? I bought the 05-06 piping for my 02 RSX and on the cat section was an O2 sensor (in the primary O2 hole). I believe the guy has K-Pro so it's not entirely certain it's an 05 O2 sensor.

Is there any way to tell the difference?

A wideband o2 sensor must be matched to the controller, which is inside the ECU. Thus only the 02-04 o2 can be used with the 02-04 ECU.