O2 sensor single to dual

[fordinator]

long story short, my truck (95 f150 five ohh) runs a single O2 senosor down in the y pipe. i am running truck duals soon, and since the headers have 2 bungs currently pluged i would like to move the O2's up there, can a single be split dual?

[PatFromJersey]

I was wanting to do the same thing to my 97, so if I find out if it can be done, I'll let you know. One option we can do, is to run an X-pipe as close to the collectors as possible, and retain the single O2 sensor in the center of the X. :up:

[05Stang-GT]

Hmmm I would think they would be two diffent data channels to the PCM...So you would probably have to find the pin-out and see where the second one goes on trucks with factory duals and then run it to that location...but I could be totally wrong :P

[PatFromJersey]

You're right Jesse, but if Ryan's truck is OBD-I (EEC-IV) like mine, there's only one Heated Oxygen Sensor Input. All the trucks with EEC-IV had Y-pipes, and one sensor before the cat. :down:

[baravelli]

Good Question. I would stay single if I could or wire the two sensors in series if I had too.
OBD-I O2 sensors measure average residual oxygen in exhaust gases. The higher the sensor output voltage, the more oxygen and ozone. Powertrain Control Module reacts by changing fuel delivery and ignition timing.
That PCM has a single O2 sensor input port. For slight performance improvement, stay single. For slight MPG improvement, go dual. My understanding is three states require an additional sensor with the additional converter. California requires the new sensor be connected in parallel which could double the voltage. In the free world, connecting two sensors in series could halve the voltage.
Personal experience has been the 302 w/OBD-1 to be fairly efficient for carbon and sulpher oxides without converters but not for nitrogen oxides. In this state, I was cat-less and passed emissions with my old Mustangs. State standards vary though.
EDIT: I forgot. New law mandates all vehicles meet California emission standards.

[fordinator]

i will be completly catless, i will just have to run a simple cross pipe if i keep it single. pat check out hookers manifold back exhaust kits. very cheap and quite good.

[baravelli]

check out hookers manifold back exhaust kits. very cheap and quite good.

Ditto!
Eliminate the O2 sensor signal all together.