1 o2 sensor- how to make it work on a dual exhaust setup
 

Hey Everyone.

kinda weird question for those exhaust exports, I am going to break this down because there is a bit to it.

DETAILS-
my car is a 81 911 sc with a 3.6 engine from a 1995 porsche 911.
my car (with 95 3.6 engine) is running s-car-go race headers with a gt3rs muffler
the oem engine has 1 o2 sensor that collects data from both headers via a cross pipe that goes into the muffler (please see random google pic below, you can see the o2 sensor where the exhaust comes together)
http://forums.pelicanparts.com/uploa...1481757311.jpg


my setup has no pipes that come together other than the muffler- please see random pic of the exhaust setup like mine)
http://forums.pelicanparts.com/uploa...1481757369.jpg


THE QUESTION>
how do I get the stock o2 sensor to read the exhaust from both sides of the engine with my setup? do I cut the muffler and weld the sensor in? do I just run off one side? is there a kit to run two?

or- what options do I have? remember this is a obd1 engine- which is different from the 96-98 obd2 setups.


thanks Gents

You use one O2 sensor in one of the headers, you don't need two. You assume that the A/F ratio is the same on both cylinder banks. I (and many others) have run this set up for years, and it works fine!

I believe the early versions of the SSIs had an option for an O2 sensor bung. It was only on one bank just like Fly911 said.

I believe that is the most common approach. You want the O2 sensor as close to the exhaust ports as possible. There shouldn't be an a meaningful variance between the left and right bank anyway.

'95m is OBD1 and has only a single O sensor input, you could put the O sensor in the muffler and get the average of both banks but most of us just put it on one side .

Mine, w/ the o sensor bung on the left side bank
http://forums.pelicanparts.com/uploa...1481826867.jpg

OBD 2 cars will have 4 inputs, 1 pre and 1 post cat on each side.

I run left side 02 sensor to DME.

I run right side 02 sensor to AFM meter in dash

Works just fine

I put a bung in each header.

I only run one sensor but I have the option of switching it to the other header if I ever wanted to use it for trouble shooting or whatever.

So far I haven't figured out a reason to test the other side yet.

Manufacturers recommend not locating a WB sensor too close to the exhaust port - for longevity purposes.

Sensor(s) located too far downstream might delay A/F readings and thus confuse accurate diagnosis.

One could install a WB sensor system that supports two wide band sensors, or two independent sensors (and two gauges). More info is better up to a point. For one off, experimental engines, a WB sensor near each exhaust port provides even more accurate cylinder-to-cylinder info.

Reminder. Installed O2 sensors must be connected to a working system less they become contaminated by exhaust byproducts.

Sherwood