There is one in the exhaust system before the catalytic converter and sometimes one after it.
On your 2003 Ford Ranger , 4.0 liter SOHC , V6 : Bank 1 is the passenger side of the engine Sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter Sensor 2 would be AFTER the exhaust exits the catalytic converter
Bank 2 is the drivers side of a V6 engine in a Ford Ranger Sensor 1 would be somewhere in the exhaust before the exhaust enters the catalytic converter ( upstream sensor )
Bank 1 is the passenger side of the engine in your 3.0 liter Ford Ranger Sensor 1 ( upstream sensor ) is in the exhaust before it enters the catalytic converter ( either in the exhaust manifold or exhaust pipe )
On your V6 engine : Bank 1 is the passenger side of the engine Sensor 1 is in the exhaust pipe ( or exhaust manifold ) before the exhaust enters the catalytic converter ( upstream )
A 1998 Ford Ranger typically has one catalytic converter, which is located in the exhaust system. However, the exact number may vary based on the engine type and specific configuration of the vehicle. Some models, especially those with dual exhaust systems, may have two catalytic converters. Always refer to the vehicle's service manual for precise information.
It is right on top of the Catalytic Converter.
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
There should be 2 (upstream) O2 sensors (one for each bank of cylinders) before the catalytic converter and only one (downstream) O2 sensor after the catalytic converter. All 3 are threaded into the exhaust system.
Bank # 1 is the passenger side of the engine Bank # 1 , SENSOR # 1 , is close to the engine in the exhaust Bank # 1 , SENSOR # 2 , is in the exhaust after the catalytic converter ( downstream )
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
I don't know about the catalytic converter (typically Rangers -at least the 4.0L V6 has 2 catalytic converters). But for the rest of the exhaust system : with 2 prebend pipes, gaskets and the muffler, you are looking at anywhere from $ 361 to $ 457.00 as of Dec 15, 2011. - it also depends on the shop who does the work. Hope this helps.