AutoCodes – GMC – P2099 2016 GMC Sierra

P2099 2016 GMC Sierra Code - Post Catalyst Fuel Trim System High Limit Bank 2

Quick Answer

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. Common causes include Exhaust system leaks, Split, kinked or improperly connected vacuum hoses, Insufficient fuel in the tank. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P2099 2016 GMC Sierra indicates Post Catalyst Fuel Trim System High Limit Bank 2.
Common causes: Common causes include Exhaust system leaks, Split, kinked or improperly connected vacuum hoses, Insufficient fuel in the tank.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 287

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 08, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2099 2016 GMC Sierra Description

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The Engine Control Module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount. The Diagnostic Trouble Code (DTC) will be set when the correction limit for a condition causing a rich or lean air/fuel ratio has been exceeded.

OBDII Code P2099 2016 GMC Sierra - Post Catalyst Fuel Trim System High Limit Bank 2 - AutoCodes.com — P2099 2016 GMC Sierra Code - Post Catalyst Fuel Trim System High Limit Bank 2

What does this mean?

What are the Possible Causes of the DTC P2099 2016 GMC Sierra?

Exhaust system leaks
Split, kinked or improperly connected vacuum hoses
Insufficient fuel in the tank
Leaks in the air induction system and air intake ducts
Missing air filter element
Cracked evaporative canister
Evaporative pipes plugged, obstructed, or leaking
Crankcase ventilation system leaking
Engine vacuum leaks
Low fuel system pressure
Contaminated fuel
Lean fuel injectors

How to Fix the DTC P2099 2016 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2099 2016 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P2099 2016 GMC Sierra code?

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Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2099 2016 GMC Sierra Code

1. What are the common symptoms of OBDII code P2099 in a 2016 GMC Sierra?

- Common symptoms of P2099 include reduced fuel efficiency, engine misfires, rough idling, and the illumination of the check engine light.

2. What does the OBDII code P2099 in a 2016 GMC Sierra indicate?

- P2099 indicates a high limit condition in the post-catalyst fuel trim system on Bank 2 of the engine.

3. What are the possible causes of OBDII code P2099 in a 2016 GMC Sierra?

- Common causes of P2099 include a failing oxygen sensor, issues with the fuel system, exhaust leaks, or problems with the catalytic converter.

4. How can I diagnose the OBDII code P2099 in my 2016 GMC Sierra?

- Diagnosing P2099 usually involves using an OBDII scanner to retrieve the code, checking for any other related codes, and conducting a thorough inspection of the post-catalyst fuel trim system components.

5. Can a dirty air filter trigger OBDII code P2099 in a 2016 GMC Sierra?

- Yes, a dirty air filter can impact the air-to-fuel mixture ratio and potentially contribute to triggering P2099 due to incorrect readings by the oxygen sensor.

6. Is it safe to continue driving with OBDII code P2099 in a 2016 GMC Sierra?

- It is not recommended to continue driving with P2099 as it can lead to long-term damage to the engine and emissions system. It's best to address the issue promptly.

7. How can I repair OBDII code P2099 in my 2016 GMC Sierra?

- Repairing P2099 may involve replacing the oxygen sensor, addressing any fuel system issues, repairing exhaust leaks, or replacing the catalytic converter if necessary.

8. Can a faulty spark plug contribute to triggering OBDII code P2099 in a 2016 GMC Sierra?

- Yes, a faulty spark plug can lead to incomplete combustion, affecting the fuel trim system and potentially causing the oxygen sensor to detect high levels of fuel trims, triggering P2099.

9. Will resetting the check engine light resolve OBDII code P2099 in a 2016 GMC Sierra?

- Resetting the check engine light may temporarily turn it off, but it will not fix the underlying issue causing P2099. It's crucial to diagnose and address the root cause of the problem.

10. How can I prevent OBDII code P2099 from recurring in my 2016 GMC Sierra?

- To prevent P2099 from recurring, it's essential to perform regular maintenance on the vehicle, such as replacing air filters, spark plugs, and oxygen sensors at recommended intervals, and addressing any issues promptly to avoid prolonged high fuel trims.