OXYGEN
2-19
IMPORTANT:
Some engines (usually off-road applications)
use a titania-type oxygen sensor. This sensor
resembles the common zirconium type, but has
an open-ended tip. The titania sensor changes
resistance when it operates. This tester is
not designed to test the titania type
sensor.
When to Test
• Related trouble codes sent by computer.
• Driveability problems such as rough running,
hesitation, stumble, poor fuel economy, poor
performance, black exhaust smoke.
Inspection
Sensor operation (see page 2-21). Poor connec-
tions at the sensor or computer.
This sensor often fails because of contamination
from fuel, oil additives, gasket sealer or an overly
rich running engine. Factors which can make a rich
running engine include: ignition system problems
(coil, distributor cap, rotor, spark plugs, wires), fuel
contaminated by engine oil, emission devices
(carbon canister, EGR valve, PCV valve, air
injection system), manifold leaks, air filter, fuel
pressure and engine not at normal operating
temperature.
HIGH
SENSOR
VOLTAGE
LOW
Lean
OPTIMUM
Rich
AIR FUEL MIXTURE
Summary of Contents for CP9087
Page 82: ...3 22 Notes...
