Ross Hunt

Ive got a 2018 chevy silverado and it runs fine, no signs of problems but i keep getting this code ( p2099 ) when i run a OBD reader on it any ideas?

oilcanhenry

Well according to what I found out, it means:

Faulty bank 2 catalytic converter.

A faulty mass air flow (MAF) sensor

A manifold air pressure sensor

Defective bank 2 O2 sensor/s Burnt, chafed, broken, or disconnected

Wiring and/or connectors bad

Engine exhaust leaks

Of all of these conditions, the Mass Air Flow (MAF) sensor is the cheapest to "fix" or clean, and it won't hurt to clean it anyhow.

It's located between your air filter and your Throttle body inlet. You can clean it with either MAF cleaner, or electrical cleaner but don't use carb or brake cleaner, or you can soak it in rubbing alcohol overnight (the cheapest way) and see if that clears it.

If you've been using an oiled air-cleaner like a K&N those can put oil on it and cause a malfunction, but if you clean it and get rid of the K&N filter it might be OK to go.

You must make sure that it is dry inside before you install it back into place. It cannot still be wet at all. A blow-dryer will speed that up or another source of low heat.

If it is not the MAF, then you have a rich condition or your catalytic converter is going south, or you have a bad 02 sensor, likely due to running rich.

It also indicates it might be the MAP sensor (Manifold Absolute Pressure) sensor as well. Those cannot be cleaned but thrown out for a new one.

Is your Chevrolet still on warranty? If so, allow the dealership to repair it.

PNW NBS Z71

P2099 code definition

Post catalyst fuel trim system too rich bank 2

What the P2099 code means

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.

What are the causes of the P2099 code?

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
  

What are the symptoms of the P2099 code?

Symptoms of this trouble code that the driver may experience would include:

• The vehicle may not accelerate properly
• The vehicle may emit black smoke upon acceleration or start up
• The Check Engine Light will be illuminated
• The engine may lack sufficient power
• The engine may stall at times
• The vehicle will have poor fuel economy
• It is possible that this code could cause no symptoms at all other than the Check Engine Light

How does a mechanic diagnose the P2099 code?

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.

Common mistakes when diagnosing the P2099 code

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.

How serious is the P2099 code?

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.

What repairs can fix the P2099 code?

Repairs that can fix this trouble code may include:

• Replace the mass air flow sensor
• Repair or replace circuitry for the mass air flow sensor
• Replace the manifold absolute pressure sensor or circuitry associated with it.
• Replace the fuel pressure regulator
• Replace the powertrain control module
• Replace the oxygen sensor(s) or circuitry associated with them.
• Replacing the intake tube that goes from the air cleaner to the throttle body.

Additional comments regarding the P2099 code

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.