There are two sensors on a 1999 Villager. The upstream sensor is located in the exhaust manifold at the front of the engine. It could be right on top mounted straight up or further down mounted sideways. The downstream sensor is located in the exhaust pipe right behind the catalytic converter. If you have a check engine light that comes on due to an indicated O2 sensor fault, the problem may not be the sensor itself. (Keep in mind that the upstream sensor actively monitors the air/fuel ratio and sends a variable feedback signal to the PCM. The PCM uses the downstream sensor for the catalyst monitor system and does not affect the air/fuel ratio). Check the wiring from the O2 sensor to the PCM for shorts or open wires. Check for proper voltage from the sensor by back probing the connector with a straight pin. Turn the ignition ON but do not start the engine. Connect a DIGITAL voltmeter TO a good ground and the positive lead (usually the center wire) of the O2 sensor SIGNAL wire at the connector. It should give a reading between 400 and 450 millivolts (.40 to .45. volts). If not, trace and repair the circuit. CAUTION: DO not probe the wires of the O2 sensor or the harness as the circuit is very sensitive to excessive circuit loads or circuit damage of any kind.
There are two.
The oxygen sensors are in the exhaust pipes on most models.
Both oxygen sensors are in the exhaust pipe, one under the front of the engine, one roughly under the passenger seat are.
Four
would like to know where the speedometer sensors are on a 1999 villager
How do you change the thermostat in 1999 Mercury Villager
Yes.
There are two oxygen sensors, one in the exhaust near the engine, one in the exhaust pipe after the second converter, roughly under the passenger seat on OBD-II vehicles.
According to the 1999 Mercury Villager Owner Guide : ( 20.0 US. gallons )
In the engine.
No, no room.
134-A