Dodge ZB 2005 Service Manual page 1230

P0420-1/1 CATALYTIC CONVERTER EFFICIENCY —
TEST
2 Inspect the Catalytic Converter for the following damage.
Damage Catalytic Converter, dent and holes.
Severe discoloration caused by overheating the Catalytic Converter.
Catalytic Converter broke internally.
Leaking Catalytic Converter.
Were any problems found?
Yes → Replace the Catalytic Converter. Repair the condition that may
→ Go To 3
No
3 Start Engine and let idle.
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
Check for exhaust leaks between the engine and the appropriate downstream O2
Sensor.
Is there any exhaust leaks?
Yes → Repair or replace leaking exhaust parts as necessary.
→ Go To 4
No
4 Check the exhaust for excessive smoke from internal oil or coolant leaks.
Is there an oil or coolant consumption condition present?
Yes → Repair engine mechanical condition as necessary and replace
→ Go To 5
No
5 Turn the ignition off.
NOTE: A new Downstream O2 Sensor along with an aging Upstream O2
Sensor may cause this trouble code to set.
Review vehicle repair history.
Has the Downstream O2 Sensor been replaced without replacing the Upstream O2
Sensor?
Yes → Replace the appropriate Upstream Oxygen Sensor.
→ Go To 6
No
6 If there are no possible causes remaining, view repair.
Repair
ACTION
have caused the failure.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Catalytic Converter.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Replace the Catalytic Converter.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
DRIVEABILITY - GAS
109
Continued
APPLICABILITY
All
All
All
All
All