DTC Troubleshooting: P2097
DTC P2097: Post Catalyst Fuel Trim System Too Rich
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
If any of the DTCs listed below are stored at the same time as DTC P2097, troubleshoot those DTCs first, then recheck for P2097.
P0133, P1172, P2A00: A/F sensor (Sensor 1)
P0134: A/F sensor (Sensor 1) heater
P0137, P0138, P0139, P2270: Secondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater
P0171, P0172: Fuel system
P0201, P0202, P0203, P0204: Fuel injector
P0300: Random misfire
P0301, P0302, P0303, P0304: No. 1?No. 4 cylinder misfire
P0351, P0352, P0353, P0354: Ignition coil

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2097 Post Catalyst Fuel Trim System Too Rich
      

1.
Problem verification:

Problem verification
?1.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

?4.
Test-drive the vehicle under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C)
A/T in D, M/T in 4th
Engine speed below 4,000 rpm
Vehicle speed between 15?75 mph (24?120 km) for 3 minutes or more

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
ENGINE SPEED
    
VEHICLE SPEED
    

?5.
Monitor the OBD STATUS for DTC P2096 with the HDS.
DTC Description
OBD STATUS
P2097 Post Catalyst Fuel Trim System Too Rich
 

Does the HDS indicate FAILED?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the secondary HO2S (Sensor 2), and the PCM.
If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-4 and recheck.?
2.
Exhaust system check:

Exhaust system check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Check for leakage, clogging, or blockage in the exhaust system.

Is there leakage in the exhaust system between the A/F sensor (Sensor 1) and the secondary HO2S (Sensor 2), or any clogging or restrations in the exhaust system?

     
YES
     
     
     
     
NO
     
     
     
Go to step 3.
3.
A/F sensor (Sensor 1 ) check (substitution):

A/F sensor (Sensor 1 ) check (substitution)
?1.
Substitute a known-good A/F sensor (Sensor 1).

?2.
Reconnect all connectors.

?3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.
Reset the PCM with the HDS.


?5.
Do the PCM idle learn procedure.

?6.
Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

?7.
Test-drive the vehicle under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C)
A/T in D, M/T in 4th
Engine speed below 4,000 rpm
Vehicle speed between 15?75 mph (24?120 km) for 3 minutes or more

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
ENGINE SPEED
    
VEHICLE SPEED
    

?8.
Monitor the OBD STATUS for DTC P2097 with the HDS.
DTC Description
OBD STATUS
P2097 Post Catalyst Fuel Trim System Too Rich
 

Does the HDS indicate PASSED?

     
YES
     
     
     
     
NO
     
     
     
If the HDS indicates FAILED, replace the secondary HO2S (Sensor 2), then do the repair verification. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3-7 and recheck.?
Repair verification (OBD STATUS check):

?1.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?2.
Reset the PCM with the HDS.


?3.
Do the PCM idle learn procedure.

?4.
Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

?5.
Test-drive the vehicle under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C)
A/T in D, M/T in 4th
Engine speed below 4,000 rpm
Vehicle speed between 15?75 mph (24?120 km) for 3 minutes or more

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
ENGINE SPEED
    
VEHICLE SPEED
    

?6.
Monitor the OBD STATUS for DTC P2097 with the HDS.
DTC Description
OBD STATUS
P2097 Post Catalyst Fuel Trim System Too Rich
 

Does the HDS indicate PASSED, FAILED, EXECUTING, or OUT OF CONDITION?

     
PASSED
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Go to step 1 and recheck.
     
EXECUTING
     
     
     
Keep the test condition until a result comes on.
     
OUT OF CONDITION
     
     
     
Meet the test condition, and check the OBD STATUS again.