you have 4 o2 sensors on the 2002 mountaineer. if you get under the car and look at the exhaust pipe where it goes up either side of the engine you will see it bolted into the exhaust, it has wires coming from it. they are the front 2, the rear 2 are about 2 feet farther to the rear (easier to see)
The oxygen sensor for bank 1 sensor 1 for a 2000 mercury mountaineer is on the cylinder #1 side.
Try replacing the upstream O2 sensor
On a 2000 Mercury Mountaineer ( 4.0 V6 and 5.0 V8 ) Bank 2 is the drivers side of the engine Sensor 1 is close to the engine BEFORE the exhaust enters the catalytic converter Sensor 2 is AFTER the exhaust has passed through the catalytic converter
On the exhaust pipe, lower, possibly near the catalytic converter.
P0133 - upstream heated O2 sensor circuit slow response ( Bank 1 ) Bank 1 is the passenger side of your engine Sensor 1 - is in your exhaust pipe before the exhaust enters the catalytic converter ( upstream )
Bank 2 is the drivers side of the engine sensor 1 is in the exhaust , close to the engine , before the exhaust passes through the catalytic converter
For a 1997 Mercury Mountaineer ( 5.0 liter V8 ) ( there are a total of 4 oxygen sensors , 2 sensors that are used with the PCM to adjust the fuel ratio that are nearest the engine on both sides , and 2 sensors that are also called catalyst monitors because they are in the exhaust after the catalytic converters ( downstream sensors ) On the passenger side of the engine in a Mercury Mountaineer ( Bank 1 ) Sensor 1 ( upstream sensor ) and Sensor 2 ( downstream sensor ) On the drivers side ( Bank 2 ) Sensor 1 ( upstream sensor ) and Sensor 2 ( downstream sensor )
O2 sensors are always located on the exhaust system.
Trouble code P0153 means: HO2S-21 (Bank 2 Sensor 1) Circuit Slow Response Try replacing the upstream O2 sensor
On a 2003 Mercury Mountaineer : In the power distribution box ( which is " live " ) located in the engine compartment on the drivers side : ( # 41 is a 15 amp mini fuse for the HEGO , VMV , CMS , PTEC ) HEGO stands for Heated Exhaust Gas Oxygen ( sensor ) You can view the 2003 Mercury Mountaineer owners manual online at : www . motorcraft service . com ( no spaces ) Click on Owner Guides ( the fuses and relays section starts on page 166 and the power distribution box diagram is on page 171 )
the exhaust, where every o2 sensor is
There are three on the 98. Two are located on the exhaust manifold basically beneath the passenger seat area. The other is on the manifold that goes to the drivers side of the engine and is located by the tranny pan.