On a Ford Ranger ( V6 engine )
Bank 2 is the drivers side of the engine
Sensor 1 would be close to the engine before the exhaust enters the catalytic converter
motorcraft . com just shows ( 1 ) oxygen sensor for all available engines in a 1991 Ford Ranger
I'm not a mechanic / technician but on a 1988 Ford Ranger there might be ( 1 ) oxygen sensor ( upstream sensor )
the o2 sensor is located on the exaust manifold
The O2 sensor after the catalytic converter.
It just has ( 1 ) oxygen sensor , before the catalytic converter ( upstream )
Where is the ford ranger 2004 revcounter sensor conected
you can breath
Where are the Bank 1 Sensor 1 oxygen sensor on a 1998 ford explorer?
Bank 1 is the passenger side of your V6 in a Ford Ranger Sensor 1 is somewhere close to the engine before the exhaust enters the catalytic converter
in the exhaust pipes behind & in front of converters
sending wrong fuel ratio mix
There is one in the exhaust system before the catalytic converter and sometimes one after it.