Cat Options for rear o2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

whitesdie · 01-13-2014, 05:00 PM

First time posting here on Zilvia, sorry if I'm repeating an old thread, done thorough research and couldn't find my exact issue.

1995 240sx ka24de, stick with about 190xxx miles
tried to smog it and failed due to high HC. levels were high but still under limit at low speed, but at high speed 270ppm limit here in NV is 220ppm
Pulled codes and got crankshaft position sensor, vehicle speed sensor, and rear o2 sensor.
So I changed out the crankshaft pos sensor, cap, rotor, oil change, oil filter, seafoamed, plugs, fuel filter, did the valve cover gasket (cause I had some oil on the old spark plug #4) and i'm changing out the vacuum hoses and all exhaust gaskets (pipe that connected to the front of the cat was missing bolt and hanging a bit)

Found out that the rear o2 connector has no sensor plugged in and I think it might be the cause of my problem. I have these stupid pacesetter headers that rid the car of the front catalytic converter and so there's no bung for the o2.
I do however have a a cat where the second cat is supposed to be located.
So i wanted advice for my options..
Should I install a bung for my o2? if so, pre cat or post cat?
Or should I replace my existing cat with a cat that has the o2 port inside it like this More Information for BOSAL 0993781

Or possibly get a new manifold that doesn't eliminate the front cat and buy the front cat with o2 port? This would be my last resort since it is the most expensive.

I would really appreciate any feedback or insight, thanks.

01-13-2014, 05:00 PM	#1
whitesdie Join Date: Apr 2013 Location: Las Vegas Age: 33 Posts: 2 Trader Rating: (0) Feedback Score: 0 reviews	Cat Options for rear o2 First time posting here on Zilvia, sorry if I'm repeating an old thread, done thorough research and couldn't find my exact issue. 1995 240sx ka24de, stick with about 190xxx miles tried to smog it and failed due to high HC. levels were high but still under limit at low speed, but at high speed 270ppm limit here in NV is 220ppm Pulled codes and got crankshaft position sensor, vehicle speed sensor, and rear o2 sensor. So I changed out the crankshaft pos sensor, cap, rotor, oil change, oil filter, seafoamed, plugs, fuel filter, did the valve cover gasket (cause I had some oil on the old spark plug #4) and i'm changing out the vacuum hoses and all exhaust gaskets (pipe that connected to the front of the cat was missing bolt and hanging a bit) Found out that the rear o2 connector has no sensor plugged in and I think it might be the cause of my problem. I have these stupid pacesetter headers that rid the car of the front catalytic converter and so there's no bung for the o2. I do however have a a cat where the second cat is supposed to be located. So i wanted advice for my options.. Should I install a bung for my o2? if so, pre cat or post cat? Or should I replace my existing cat with a cat that has the o2 port inside it like this More Information for BOSAL 0993781 Or possibly get a new manifold that doesn't eliminate the front cat and buy the front cat with o2 port? This would be my last resort since it is the most expensive. I would really appreciate any feedback or insight, thanks.