That should be the O2 sensor just before the catalytic converter.
That should be the sensor located after the catalytic converter.
Bank 1 sensor 3 would be the O2 sensor after the catalytic converter.
That would be the O2 sensor after the catalytic converter.
Need more info, is this the 4 cylinder or 6 cylinder engine and which sensor on bank 1.
Bank 1, on a 4.3 L engine would be on the drivers side.
Passenger side exhaust pipe directly after the exhaust manifold.
Assuming this is a V-6, bank 1 sensor 1 would be the first O2 sensor in the exhaust on the drivers side of the engine.
Downstream ... This is after the Catalyst Converter.
The 1994 S10 uses a MAP sensor, not a MAF sensor. We need to know size engine you have in that S10.
That vehicle has several oxygen sensors and they are all threaded into the exhaust at various points.
Bank 2 would be the passenger side of the engine, sensor 1 would be the first sensor after the passenger side exhaust manifold. It is best reached from under the vehicle.
It is threaded into the header pipe directly after the exhaust manifold on the passenger side.