I just tried to replace the oxygen sensor in my 81 toyota pickup SR5 but couldn't find it. It looks like the intake manifold has a blank spot right where the sensor should go. Does anyone know what is going on? Did someone put an aftermarket manifold on to eliminate the o2 sensor? I looked around and could not find the wiring harness for the sensor. Did 1981 toyota's have o2 sensors at all? Any info would be appreciated.
Oxygen sensors don't go in the intake manifold. The go in either the exhaust manifold or exhaust pipe.
January, 24, 2011 AT 12:48 AM
O2 sensor Mounted On Exhaust Manifold Applicable to: 1981-83 Models
January, 24, 2011 AT 1:09 AM
Sorry, I meant exhaust manifold. Here is a picture
January, 24, 2011 AT 1:13 AM
I'm looking at the diagram and I just don't know where or what it bolts into. Should go into the exhaust manifold but there is just a blank spot there.
January, 24, 2011 AT 1:17 AM
Do you have a check engine light? If you have a non-electronic carb, it may not have one.
January, 24, 2011 AT 1:28 AM
No check engine light that I know of. Carburetor only has a couple of wires going to it and they are for the fuel cut solenoid and the choke. 3 wires total. So it looks kind of like the engine doesn't have an oxygen sensor. Can anyone explain why I might be getting only 18 mpg out of this little 4 cyl? I figured I would be getting at least 25.
January, 24, 2011 AT 1:31 AM
It's 30 years old and carburetors were never very efficient. I don't know why your expectations are so high.
January, 24, 2011 AT 1:41 AM
There's a lot of contributing factors within the vehicle subsystems to mess with fuel economy such as the following-Badly needed tune-up and adjustments, carbueration problem, slipping clutch, brake dragging, wheel alignment and tires/suspension problem and the list goes on in my checklist
January, 24, 2011 AT 1:58 AM
Thanks for your input guys. You've helped a lot. I was just baffled that the truck didn't have an o2 sensor. Again, thanks for the quick replies