For the 1993 Toyota Tercel, the O2 sensor has three different wire colors. These colors are: black, blue, and white.
Under the passenger side of the truck, across from the o2 sensor closest to the engine on the muffler.
The O2 sensor on a Toyota Corolla is located on the exhaust manifold. The O2 sensor properly reads the air fuel ratio to tell the engine how much fuel to use.
On a 1997 Toyota T100 V6, the oxygen (O2) sensors are located in two main places: one upstream (pre-catalytic converter) and one downstream (post-catalytic converter). The upstream O2 sensor is typically found on the exhaust manifold or just before the catalytic converter, while the downstream sensor is located after the catalytic converter in the exhaust system. To access them, you may need to lift the vehicle and may require special tools to remove them. Always ensure the engine is cool before attempting to work on the exhaust system.
See related link which includes instructions for testing any O2 sensor.
The 1993 Chevrolet K 1500 pickup truck 02 sensor is on the back of the air cleaner housing. The O2 sensor should be labeled as such.
The one closest to the exhaust manifold is the upstream O2 sensor.
O2 sensor
There is no sensor by this name in a toytota. The Toyota air/fuel sensor is also known as the upstream air/fuel sensor. The Toyota downstream sensor is also known as the downstream O2 sensor.
It screwed in to the exhaust manifold. To change it you unplug the sensor and unscrew it with an O2 sensor socket.
I'm not sure about 40% but it WILL reduce gas mileage I'm not sure about 40% but it will for sure reduce your gas mileage. 40% does extremely high for just one O2 sensor
Bank 2 sensor 1 is the O2 sensor in the exhaust manifold closest to the firewall.Cut and paste the link below for a detailed fix with pics of the O2 sensor repair."http://polifrogblog.blogspot.com/2009/11/sienna-o2-sensor-change.html"