00si420

I have a 2000 civic si with a greddy header. I'm using the 2nd o2 sensor for the header but the check engine light is on. Its running really rich right now. The 1st o2 sensor is disconnected. I heard something about using a spark plug non fouler... would a spark plug non fouler fix the problem?

SOHC_4dr

you just stated your issue. also the first o2 is on the header, 2nd is after the cat

1LowSol

+1

00si420

thanks guys!

Redbone

both have to be plugged in if u r using an OBD2 ECU. U can use an O2 simulator on the 2nd.

00si420

thanks redbone... is there any other way besides a o2 sim to cover the 2nd sensor? btw, i was just in tempe, az and loved it there!

Redbone

as long as u were here in winter dont come in summer u'll hate it. You can search for p0420 code on here and some1 has prob talked about other ways to make it go away. I think the ECU also looks for temp reading on the 2ndary so it still has to be plugged in but O2 sim isnt that expensive as long as you have both hooked up and plugged in the correct ports. This is where i got mine from so u might wanna check it out. http://www.o2simulator.com/

SOHC_4dr

why would you want a sim???

BLACK93CIVICDXCOUPE

I have this same problem in my 00Si

Redbone

if hes running obd2 with aftermarket cat its prob gonna throw p0420 so u'd need a sim on the 2ndary. If you're running stock cat then disregard running a sim.