DTC P2099 (2016 2017 2018 2019 2020)

DTC P2099  : Post Catalyst Fuel Trim System Too Rich (Bank 2)

NOTE: Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the A/T System (2014 2015), or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016) .
• If any of the DTCs listed below are stored at the same time as DTC P2099, troubleshoot those DTCs first, then recheck for P2099.

  P0153, P1174, P2A03: Front A/F sensor (Sensor 1, Bank 2)

  P0154: Front A/F sensor (Sensor 1, Bank 2) heater

  P0157, P0158, P0159, P2272: Front secondary HO2S (Sensor 2, Bank 2)

  P0161: Front secondary HO2S (Sensor 2, Bank 2) heater

  P0174, P0175: Fuel system

  P0201, P0202, P0203, P0204, P0205, P0206: Fuel injector

  P0300: Random misfire

  P0301, P0302, P0303, P0304, P0305, P0306: No. 1-No. 6 cylinder misfire

  P0351, P0352, P0353, P0354, P0355, P0356: Ignition coil

  P219B: Front bank cylinder A/F variation

DTC (PGM-FI)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

   - 3. Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) 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)
   • Transmission in D
   • Engine speed below 4, 000 rpm
   • Vehicle speed between 15-75 mph (24-120 km/h) for 3 minutes or more

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

   - 5. Monitor the OBD STATUS for DTC P2099 with the HDS.

   DTC Description	OBD STATUS
   P2099 Post Catalyst Fuel Trim System Too Rich (Bank 2)

   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 front A/F sensor (Sensor 1, Bank 2), front secondary HO2S (Sensor 2, Bank 2), and the PCM.If the HDS indicates EXECUTING, keep the test conditions until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-4 and recheck.

2. Cylinder A/F variation check

   -1. Start the engine.

   - 2. Hold the engine speed at 3, 000 rpm without load (in P or N) 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.

   CYLINDER A/F TEST

   Is the result OK?

   YES 

   Go to step 3.

   NO 

   Go to the troubleshooting for DTC P219B .

3. 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 front A/F sensor (Sensor 1, Bank 2) and front secondary HO2S (Sensor 2, Bank 2), or any clogging or restrictions in the exhaust system?

   YES 

   Repair or replace the exhaust system - Refer to: Warm Up TWC Removal and Installation, or Under-Floor TWC Removal and Installation .

   NO 

   Go to step 4.

4. A/F sensor (Sensor 1) check (substitution)

   -1. Substitute a known-good front A/F sensor (Sensor 1, Bank 2).

   - 2. Reconnect all connectors.

   - 3. Turn the vehicle to the ON mode.

   - 4. Reset the DTC with the HDS.

   Reset PCM

   - 5. Do the PCM idle learn procedure.

   - 6. Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) 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)
   • Transmission in D
   • Engine speed below 4, 000 rpm
   • Vehicle speed between 15-75 mph (24-120 km/h) for 3 minutes or more

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

   - 8. Monitor the OBD STATUS for DTC P2099 with the HDS.

   DTC Description	OBD STATUS
   P2099 Post Catalyst Fuel Trim System Too Rich (Bank 2)

   Does the HDS indicate PASSED?

   YES 

   Replace the original front A/F sensor (Sensor 1, Bank 2) .

   NO 

   If the HDS indicates FAILED, replace front secondary HO2S (Sensor 2, Bank 2) , then recheck. If the HDS indicates EXECUTING, keep the test conditions until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 4-7 and recheck.