Question about 2002 Mercury Villager
2002 PCED OBDII-Villager
SECTION 1: Description and Operation
Catalyst and Exhaust System
The catalytic converter and exhaust system work together to control the release of harmful engine exhaust emissions into the atmosphere. The engine exhaust gas consists mainly of nitrogen, carbon dioxide and water vapor. However, it also contains carbon monoxide, oxides of nitrogen, hydrogen, and various unburned hydrocarbons. Carbon monoxide, oxides of nitrogen, and hydrocarbons are major air pollutants, and emission into the atmosphere must be controlled.
The exhaust system consists of an exhaust manifold combined with a pre-catalytic converter, upstream heated oxygen sensor (HO2S11), (located just in front of the pre-catalytic converter), three way catalytic converter (TWC), downstream heated oxygen sensor (HO2S12) (located in front of the TWC), a muffler and an exhaust tailpipe.
Heated Oxygen Sensors The Villager is equipped with both upstream and downstream heated oxygen sensors (HO2S) (Figure 1). The upstream heated oxygen sensor (HO2S11) is used to control engine fuel flow. The sensor detects the concentration of oxygen in the exhaust gas and sends a signal to the powertrain control module (PCM). In a rich condition, the HO2S will output a voltage of 0.6 volts or greater, and in a lean condition a voltage of 0.4 volts or less will be output.
The downstream heated oxygen sensor (HO2S12) is used primarily for monitoring the efficiency of the catalytic converter system. The HO2S12 works in a similar way to the HO2S11 but only indicates to the PCM that the catalyst is functioning properly. In the event that the HO2S11 fails, fuel control will be switched over to the HO2S12 and the malfunction indicator lamp (MIL) will be illuminated. This allows the vehicle to operate with fewer emissions, even with a sensor failure.
Figure 1: Typical Heated Oxygen Sensor (HO2S)
Posted on Mar 07, 2009
"Bank one" is the bank of cylinders that starts with the #1 cylinder. In this case this will be the bank of three cylinders that is closest to the firewall. Sensor #1 refers to the O2 sensor that is between the engine and the catalytic converter. So the Bank 1, sensor 1, will be the O2 sensor that is mounted in the rear exhaust manifold or tubing just before the cat.
Posted on May 16, 2009
The sensor you indicate would be on the manifold of the head containing cyl.# 1, top sensor (prior to catalytic conv.) 6 cyl. engine. 4 cylinder would be sensor on exhaust manifold. Confirm sensor failure prior to replacing as chrysler harness connectors are known for pin failures at 02 sensor connections. Inspect for burnt pins and cracked/chaffed wires first before changing sensor.
Posted on Jan 30, 2010
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Posted on Jan 02, 2017
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