P2099 - POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 2

Storing the P2099 OBDII fault code means that the vehicle’s computer has detected an excessive amount of unburned hydrocarbon molecules in the exhaust stream downstream of the catalytic converter. On the other hand, it also means the PCM cannot correct the air/fuel mixture.

The O2 Sensor is designed to provide the Powertrain Control Module (PCM) with real-time information about the percentage of oxygen that is present in the engine exhaust compared to the environment oxygen.

• Check Engine light ON.
• Lower fuel efficiency.
• Loss of overall engine performance.
• Other trouble codes

Reasons for setting the P2099 OBD2 diagnostic code:

• The catalytic converter (TWC) could be damaged.
• The Mass Air Flow (MAF) sensor may be faulty.
• The Oxygen (O2) Sensor on Bank 2 may be damaged.
• The system may have faulty cables or connectors.
• Perhaps there are exhaust leaks from the engine.

The steps to troubleshoot problems associated with OBDII DTC P2099 are as follows:

• Consult the Technical Service Bulletins (TSB) available for your car model. Also, before diagnosing this code, verify that no other diagnostic codes are stored. If this is the case, repair these codes first.
• Check wires and connectors that are associated with the system. Pay attention to wires that are near the exhaust or other components that involve high temperatures. Burned wires or corroded connectors should be replaced.
• Check the resistance, signal ground, and voltage of the Oxygen Sensor. Compare the results you get with the manufacturer's specifications. If there are inconsistencies with the resistance, replace the O2 Sensor.