Step
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
1
Was the check performed?
1. Install a scan tool to the Data link Connector
(DLC).
2
2. Turn the ignition ON.
Are any component Diagnostic Trouble Codes
(DTCs) set?
1. Visually/physically check the following:
2. Exhaust system for a leak.
3
3. Heated Oxygen Sensor (HO2S).
Is a problem found?
Repair the exhaust system as needed.
4
Is the repair complete?
Replace the Three Way Catalytic Converter (TWC).
5
Is the repair complete?
1. Using the scan tool, clear the Diagnostic Trouble
Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
6
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?
Check if any additional DTCs are set.
7
Are any DTCs displayed that have not been
diagnosed?
DAEWOO M-150 BL2
DTC P0420 – Catalyst Low Efficiency
Action
ENGINE CONTROLS 1F – 209
Value(s)
Yes
–
Go to Step 2
–
Go to
Applicable DTC
table
–
Go to Step 4
–
Go to Step 6
–
Go to Step 6
–
Go to Step 7
Go to
Applicable DTC
–
table
No
Go to
"On-Board
Diagnostic
System Check"
Go to Step 3
Go to Step 5
–
–
Go to Step 2
System OK