Diagnostic Test

WARNING: This page is about a different car, the 2007 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

1) ACTIVE DTC
NOTE: A new rear O2 Sensor along with an aging front O2 Sensor may cause the DTC to set. Review the repair history of the vehicle before continuing.

NOTE: If an O2 Sensor DTC set along with the Catalytic Converter Efficiency DTC diagnose the O2 Sensor DTC(s) before continuing.

NOTE: Check for contaminants that may have damaged the O2 Sensor and Catalytic Converter: contaminated fuel, unapproved silicone, oil and coolant, repair necessary.

Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes
1. Go to 2).
No
1. Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) VISUALLY INSPECT CATALYTIC CONVERTER
Inspect the Catalytic Converter for the following damage.

Damage Catalytic Converter, dents or holes.

Severe discoloration caused by overheating the Catalytic Converter.

Catalytic Converter broke internally.

Leaking Catalytic Converter.

Were any problems found?

Yes
1. Replace the Catalytic Converter. Repair the condition that may have caused the failure.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 3).
3) CHECKING THE EXHAUST SYSTEM FOR LEAKS
Perform the diagnostic procedure for CHECKING THE EXHAUST SYSTEM FOR LEAKS .

Were any problems found?

Yes
1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 4).
4) ENGINE MECHANICAL CONDITION
Check the exhaust for excessive smoke caused by an internal problem in the engine.

Is an engine mechanical condition present?

Yes
1. Repair the engine mechanical condition as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 5).
5) AGING O2 SENSOR
A new rear O2 Sensor along with an aging front O2 Sensor may cause the DTC to set.

Review the vehicles repair history.

Has the rear O2 Sensor been replaced without replacing the front O2 Sensor?

Yes
1. Replace the Front O2 Sensor as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 6).
6) CATALYTIC CONVERTER
If there are no possible cause remaining, view repair.

Repair
1. Replace the Catalytic Converter.
2. Perform POWERTRAIN VERIFICATION TEST .