Two O2 sensors?

[KarlA]

Hi there

Just about to remove the old cat and muffler ready for my new cat bypass / muffler (Monty)...

Noticed that there are two sensors on the old catalytic converter, one at the entry to the cat (first picture) and one at the exit of the cat / entry of the muffler (second picture).

Presume that one of them (the one at the entry of the cat) is the O2 sensor - what's the other one??

Also, my new cat bypass only has one hole... any ideas?

Thanks

Karl

[KarlA]

Forgot to mention it is a Japan delivered 1981 SC

[KarlA]

6C on the drawing, but nothing to be found on the parts list...

[Bill Verburg]

The Japanese market cars had a temperature senor in addition to the o sensor

[KarlA]

Thanks Bill

Do I need to keep the temp sensor connected? It would mean drilling a hole and welding in a bung in my new shiny stainless cat bypass...

What happens if I don't connect it?

Karl

[juanbenae]

Originally Posted by Bill Verburg

The Japanese market cars had a temperature senor in addition to the o sensor

where on the CIS system does it terminate? warm up regulator? or is it more like an EGR valve like the earlier 78-79 3.oL had?

[Bill Verburg]

Originally Posted by KarlA

Thanks Bill

Do I need to keep the temp sensor connected? It would mean drilling a hole and welding in a bung in my new shiny stainless cat bypass...

What happens if I don't connect it?

Karl

Don't know I never looked into it.

[Bill Verburg]

Originally Posted by juanbenae

where on the CIS system does it terminate? warm up regulator? or is it more like an EGR valve like the earlier 78-79 3.oL had?

Don't know I never looked into it.

[juanbenae]

maybe the OP can trace it back to where it lands for our knowledge base? if it turns to a hard copper line running to the back side of the CIS on the passenger side it may be akin to the earlier equipped EGR valve 3.oL motors.

curious minds want to know

[86 911 Targa]

There are four O2 sensors on our Subaru.

Gerry

[KarlA]

Followed the cables today, both go to the engine bay, but neither of them is connected...

I have found a connecting end for the temp sensor but not for the O2 sensor... where should that one be? (Where should the O2 sensor connect to?)

Thanks

Karl

[Bill Verburg]

Originally Posted by 86 911 Targa

There are four O2 sensors on our Subaru.

Gerry

From 1996 My all US cars are OBD2 compliant, this requires a pre & post cat. O sensor for each cat.

[KarlA]

Hi there

Still struggling to find where the O2 sensor connects to in the engine bay - any ideas anyone?

Thanks

Karl

[76FJ55]

O2 connector should be attached to a bracket mounted to the body below the fuel filter. The temp sensor would have originally triggered a light and buzzer to alert you the cat is overheating signaling you should shut down the engine. It will cause no I'll effects to just leave it off.

[jrbennett]

From what I remember the Japan spec 911s also have a light in the dash that displays (EX), it's between the tach and speedo, the same place as the US spec (O2) sensor light.
You can leave the sensor off, it will have no effect.

As for the O2 sensor plug it should be below the fuel accumulator and filter.

It's a yellowish/whit connection with a green wire on one side and a metal tab for the sensor to plug onto on the other end

Here's some pics from a Pelican Article

[KarlA]

Thanks all, much appreciated

Karl