INSTALLATION
(1) Position the MAF sensor to air cleaner housing
and install the retaining screws (Fig. 24).
(2) Connect the air intake hose to the MAF sensor
and tighten clamp.
(3) connect the MAF wiring harness connector.
(4) Connect negative battery cable.
O2 SENSOR
DESCRIPTION
The wide band oxygen sensor measures the oxygen
content in the exhaust gas to monitor EGR. The sen-
sor is mounted in the exhaust pipe at a 30 degree
angle to prevent the collection of moisture between
the sensor housing and element. The sensor is
located close to the turbocharger for a quicker
response time.
The oxygen sensor has five wires (heater power
and ground, reference voltage, and 2 wires for a
pump cell). The oxygen sensor connects to a six wire
harness connector. A non serviceable trimming resis-
tor is built into the sensor connector. The resistance
is dependent on the over all length and type of sen-
sor.
OPERATION
The O2 sensor is a planar zirconium dioxide (ZrO2)
dual cell limiting current probe with a integral
heater. The term wide ban, refers to the ability of the
O2 sensor to generate a clear signal over a wide air-
fuel ratio measuring range. As a dual sensor, it incor-
porates a second O2 chamber (oxygen pump cell),
which requires a separate voltage supply.
The sensor element combines a sensor cell (8) and
an oxygen pump cell (9). Both cells are made of zir-
conium-dioxide (ZrO2) and are coated with porous
platinum electrodes. The sensor cell operates just
like a typical O2 sensor. The oxygen pump cell trans-
port oxygen ions when voltage is applied.
A gas sample chamber (5) is sandwiched between
the oxygen pump cell and the sensor cell. A pump
electrode and sensor cell electrode are located in the
sample chamber. A sample passage (10) connects the
sample chamber to the surrounding exhaust gas. A
sensor cell electrode is located in the reference air
channel (6), which connects to the outside air (Fig.
25).
Fig. 24 MANIFOLD AIR FLOW SENSOR
1 - WIRING HARNESS
2 - AIR INTAKE HOSE
3 - CLAMP
4 - MAF SENSOR
5 - AIR CLEANER HOUSING
VA
FUEL INJECTION
14 - 45