Note
1. Connect the WDS or equivalent and monitor PIDs as following.
2. Begin to monitor the appropriate PIDs.
3. Drive the vehicle for 10 min at 65-96 km/h {40-60 mph}
to allow the front catalytic converter to reach operating temperature.
4. Stop the vehicle and leave it in a safe place.
5. Let the engine idle.
6. Record PIDs for 1 min.
7. Select the appropriate PIDs and read the graph.
8. Count the number of times (inversions) that the upstream HO2S graph line actually crosses the 0.5 V
line.
9. Count the number of times (inversions) that the downstream HO2S graph line actually crosses the 0.5 V
line.
Note
10. Using the following equation, calculate the value of ratio.
Equation
RATIO = Upstream HO2S inversion ÷ downstream HO2S inversion
or more or there is no downstream HO2S inversion, the TWC is functioning properly.
the TWC is not functioning properly. Replace the TWC.
Upstream HO2S graph line example
Downstream HO2S graph line example 1
Equation
RATIO = 30 inversions (upstream HO2S inversions) ÷ 5 inversions (downstream HO2S
inversions) = 6.0 (good WU-TWC)
Downstream HO2S graph line example 2
Downstream HO2S graph line example 3
Equation
RATIO = 30 inversions (upstream HO2S inversions) ÷ 27 inversions (downstream
HO2S inversions) = 1.1 (bad converter)
Mazda 6 Service Manual: Heated oxygen sensor (ho2s) inspection
HO2S Voltage Inspection
Note
Perform the following inspection only when directed.
1. Warm up the engine and run it at idle.
2. Disconnect the HO2S connector.
3. Connect the voltmeter test leads to the following HO2S terminals:
HO2S (front and rear)
- (+) leadterminal A
- (-) le ...
Mazda 6 Service Manual: Front map light removal/installation
1. Disconnect the negative battery cable.
2. Remove in the order indicated in the table.
3. Install in the reverse order of removal.
Front Map Light Removal Note
1. Insert a tape-wrapped flathead screwdriver into the gap between the
headliner and the front map light.
2. Push the hooks to ...