Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

The most likely cause for this DTC is a deteriorated or contaminated HO2S 1.
Depending on the state of HO2S deterioration, this code may not reset or may be very difficult to reset.
If the HO2S deterioration is significant enough, other HO2S DTCs may set or be present in concurrence with this DTC.
Attempt to compare the activity of both the affected bank HO2S 1 and HO2S 2 to the known good bank using the live plot feature of the scan tool. Operate the vehicle under various load and vehicle/engine speed conditions. Look for any indication of improper operation or contamination of the affected bank HO2S 1 or HO2S 2.
If an intermittent condition exists, refer to Intermittent Conditions .

DTC P2097 or P2099

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module (ECM) Connector End Views
1	Did you perform the Diagnostic System Check-Engine Controls?	-	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	IMPORTANT: This code may be set due to a slow or unresponsive HO2S 1 or HO2S 2. Operate the engine at 2,000 RPM for at least 1 minute, then allow the engine to return to idle. Vary the engine speed from idle to 3,000 RPM several times within 5 seconds. Observe the affected HO2S 1 parameter with a scan tool. Does the voltage fluctuate above and below the specified range?	400-597 mV	Go to Step 3	Go to Step 5 in DTC P0134 or P0154
3	IMPORTANT: This code may be set due to a slow or unresponsive HO2S 1 or HO2S 2. Vary the engine speed from idle to 3,000 RPM several times within 5 seconds. Observe the affected HO2S 2 parameter with a scan tool. Does the voltage respond instantly to the above action?		Go to Diagnostic Aids	Go to Step 4 DTC P0140 or P0160