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P2099 is a diagnostic trouble code (DTC) for "Post Catalyst Fuel Trim System Too Rich Bank 2". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
Post catalyst fuel trim system too rich bank 2
This trouble code indicates that the powertrain control module is malfunctioning in its ability to control fuel trims. Fuel trims are what the powertrain control module uses to determine whether to add fuel or remove fuel in order to keep the air/fuel ratio correct for that particular vehicle.
Some potential causes of this trouble code may include:
The mass air flow sensor could be malfunctioning
The mass air flow sensor’s circuitry could be damaged
The air inlet tubing connected to the intake manifold could have a vacuum leak allowing unmetered air to enter the engine
The oxygen sensor(s) or circuitry could be damaged
Anything that could cause a rich condition, such as a faulty fuel pressure regulator or manifold absolute pressure sensor
The powertrain control module could be malfunctioning
Symptoms of this trouble code that the driver may experience would include:
A mechanic may start diagnosing this issue by using an OBD-II scanner to verify the fuel trims. At this point, the mechanic would then visually inspect the air intake system of the engine to make sure that all parts are in good condition and are working properly, paying close attention to the mass air flow sensor. If the problem is not found here, the mechanic would then go under the vehicle to inspect the fuel and exhaust systems.
During this inspection, the mechanic would check the fuel pressure regulator and the oxygen sensors for proper function. The manifold absolute pressure sensor would also be checked at this time. If the problem still has not been confirmed, the mechanic would then use a high tech scan tool to test the powertrain control module using the manufacturer’s recommended procedure.
Once the cause of the problem has been identified, the mechanic would relay all his/her findings over to the customer and recommend the correct repair. At this point, it would be left up to the customer to make a repair decision.
A common mistake when diagnosing any fuel trim code would be to replace the mass air flow sensor without testing it since it is the most common cause of fuel trim codes. It is very important to utilize all diagnostic material available to you in order to diagnose Check Engine Lights correctly. Check Engine Lights are the most common cause of misdiagnosis of any system on the vehicle.
The seriousness of this issue depends on the amount and severity of the symptoms that are associated with it. If the engine does not run properly and is causing the driver to be late to work or stranded on the side of the road, I would consider this code to be serious. If this code does not have any symptoms associated with it other than a Check Engine Light, this code would be low on the seriousness scale. It is important to note, however, that if a fuel trim code is stored for a long period of time, damage to the catalytic converters may result.
Repairs that can fix this trouble code may include:
Although this code is not very serious, if no symptoms are associated with it, it is still important to note that small damages can lead to larger damages. Catalytic converters can be a lot more costly than some of the sensors that could potentially be causing this trouble code. It is best to have the issue diagnosed and repaired as soon as possible even if no symptoms exist. This will help prevent further damage to the vehicle’s powertrain.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230