DTC Troubleshooting: P2096, P2097

DTC P2096: Post Catalyst Fuel Trim System Too Lean
DTC P2097: Post Catalyst Fuel Trim System Too Rich

NOTE:

Before you troubleshoot, review the general troubleshooting information.

If any of the DTCs listed below are stored at the same time as DTC P2096/P2097, troubleshoot those DTCs first, then recheck for P2096/P2097.

P0130, P0133, P2195, P2A00: A/F sensor (Sensor 1)

P0134, P0135: A/F sensor (Sensor 1) heater

P0137, P0138, P0139, P2270, P2A01: Secondary HO2S (Sensor 2)

P0141: Secondary HO2S (Sensor 2) heater

P0171, P0172: Fuel system

P0201, P0202, P0203, P0204: No. 1?No. 4 cylinder Fuel injector

P0300: Random misfire

P0301, P0302, P0303, P0304: No. 1?No. 4 cylinder misfire

P0351, P0352, P0353, P0354: No. 1?No. 4 cylinder Ignition coil

P219A: Cylinder A/F variation

DTC Description	Confirmed DTC	Pending DTC
P2096 Post Catalyst Fuel Trim System Too Lean
P2097 Post Catalyst Fuel Trim System Too Rich

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Start the engine.

?4.	Hold the engine speed at 3,000 rpm without load (CVT 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)
	CVT in D, M/T in 4th or 5th
	Engine speed below 4,000 rpm
	Drive at a steady speed between 15?75 mph (24?120 km/h) for 70 seconds or more

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

?6.

Monitor the OBD STATUS for DTC P2096 and/or P2097 with the HDS.

DTC Description	OBD STATUS
P2096 Post Catalyst Fuel Trim System Too Lean (Bank 1)
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), secondary HO2S (Sensor 2), and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot. If the HDS indicates EXECUTING, keep the test conditions until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-5 and recheck.?

Cylinder A/F variation check:

Cylinder A/F variation check

?1.	Start the engine.

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

?3.

Check under these conditions:

	A/C off
	All electrical loads off

?4.	Do the CYLINDER A/F TEST in the INSPECTION MENU three times with the HDS.

Is the result OK?


	YES

Go to step 3.


	NO

Go to the troubleshooting for DTC P219A.?

Exhaust system check:

Exhaust system check

?1.	Turn the vehicle to the OFF (LOCK) 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 secondary HO2S (Sensor 2), or any clogging or restrictions in the exhaust system?


	YES

Repair or replace the exhaust system.?


	NO

Go to step 4.

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 vehicle to the ON mode.

?4.	Clear the DTC with the HDS.

?5.	Do the PCM idle learn procedure.

?6.	Start the engine.

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

?8.

Test-drive the vehicle under these conditions:

	Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
	CVT in D, M/T in 4th or 5th
	Engine speed below 4,000 rpm
	Drive at a steady speed between 15?75 mph (24?120 km/h) for 70 seconds or more

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

?9.

Monitor the OBD STATUS for DTC P2096 and/or P2097 with the HDS.

DTC Description	OBD STATUS
P2096 Post Catalyst Fuel Trim System Too Lean
P2097 Post Catalyst Fuel Trim System Too Rich

Does the HDS indicate PASSED?


	YES

Replace the original A/F sensor (Sensor 1).?


	NO

If the HDS indicates FAILED, replace secondary HO2S (Sensor 2). If the HDS indicates EXECUTING, keep the test conditions until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 4-8 and recheck.?