Engine-CodesGMC – P0174 GMC

P0174 GMC Code - Fuel Trim System Lean Bank 2

Quick Answer

When the OBD-II system detects that the fuel trim on Bank 2 of the engine is too lean, it triggers the P0174 code. Common causes include Vacuum leaks, Faulty oxygen sensor, Clogged fuel injectors. 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
P0174 GMC indicates Fuel Trim System Lean Bank 2.
Common causes
Common causes include Vacuum leaks, Faulty oxygen sensor, Clogged fuel injectors.
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.
Table of contents Created and updated by William Orellana on Aug 18, 2024
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Code P0174 GMC Description

When the OBD-II system detects that the fuel trim on Bank 2 of the engine is too lean, it triggers the P0174 code. This means that the engine is receiving too much air and not enough fuel, leading to a lean air-fuel mixture. This can result in poor performance, reduced fuel efficiency, and potential damage to the engine over time. The fuel trim system is responsible for adjusting the air-fuel mixture to ensure optimal combustion and engine performance. A lean condition on Bank 2 could be caused by issues such as a vacuum leak, faulty oxygen sensor, fuel injector problems, or a malfunctioning mass airflow sensor.

OBDII Code P0174 GMC - Fuel Trim System Lean Bank 2
P0174 GMC Code - Fuel Trim System Lean Bank 2

Common Causes of P0174 GMC

  1. Vacuum leaks
  2. Faulty oxygen sensor
  3. Clogged fuel injectors
  4. Malfunctioning mass airflow sensor
  5. Fuel pressure regulator issues

Symptoms of P0174 GMC

  1. Reduced engine performance
  2. Poor fuel economy
  3. Rough idling or stalling
  4. Engine misfires
  5. Check Engine Light illuminated

How to Fix P0174 GMC

  1. Perform a visual inspection of vacuum hoses and intake manifold for leaks
  2. Check and replace oxygen sensor if necessary
  3. Clean or replace fuel injectors
  4. Test and replace mass airflow sensor if faulty
  5. Inspect and replace fuel pressure regulator if needed

Cost to Fix P0174 GMC

The cost of repairing a P0174 code can vary depending on the specific cause of the lean condition. On average, the cost of parts for this repair can range from $100 to $500, with labor costs adding an additional $100 to $300. Keep in mind that diagnostic time and labor rates can vary, so it's best to consult with a mechanic for a more accurate estimate based on your vehicle's make and model.

Tech Notes for P0174 GMC

The P0174 code means that more air than gasoline is detected in the exhaust gases exiting the combustion chamber. If the P0174 is set in along with the P0171 code, it is highly likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replace the air filter and clean the Mass Air Flow (MAF) Sensor. If the problem persists the MAF or Front Heated Oxygen (O2) Sensor will need to be replaced.

Click Here to Learn What is Bank 1 and Bank 2

There are Factory Service Bulletins for the following GMC models:

2000-2013 GMC All Models:
2000-2013 GMC Factory Service Bulletin OBDII Code P0174

2005-2006 GMC Envoy Models
2007 GMC Yukon, Yukon Denali, Yukon XL Denali, Yukon XL with 5.3L or 6.0L Vortec V8 Engine
GMC Factory Service Bulletin OBDII Code P0174




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Information for Specific GMC Models

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 P0174 GMC Code

1. What are the common symptoms of OBDII code P0174 GMC?

- Common symptoms include rough idling, poor acceleration, decreased fuel efficiency, and potential engine misfires.

2. What does the OBDII code P0174 GMC indicate?

- The code indicates a lean condition in the fuel trim system on Bank 2 of the engine, typically caused by a lack of fuel delivery relative to the amount of air entering the engine.

3. What are some potential causes of OBDII code P0174 GMC?

- Common causes include a vacuum leak, faulty oxygen sensor, clogged fuel filter, malfunctioning mass airflow sensor, or a leaking intake manifold gasket.

4. How can I diagnose the cause of OBDII code P0174 GMC?

- Diagnosing the issue may involve conducting a visual inspection for damaged hoses, using a scan tool to monitor data from oxygen sensors and fuel trims, and performing a smoke test to detect vacuum leaks.

5. Can a clogged fuel injector cause OBDII code P0174 GMC?

- Yes, a clogged or malfunctioning fuel injector on Bank 2 can disrupt the fuel delivery balance, leading to a lean condition and triggering the P0174 code.

6. How can I repair OBDII code P0174 GMC?

- Repair options may include replacing faulty oxygen sensors, fixing vacuum leaks, cleaning or replacing clogged fuel filters, addressing fuel injector issues, or repairing intake manifold gasket leaks.

7. Is it safe to continue driving with OBDII code P0174 GMC?

- It is not recommended to continue driving with this code unresolved, as it can lead to further engine damage and potentially cause more costly repairs down the line.

8. Can a dirty air filter trigger OBDII code P0174 GMC?

- A dirty air filter can restrict airflow to the engine, causing an imbalance in the air-fuel mixture and potentially triggering the P0174 code if left unaddressed.

9. Will resetting the OBDII code P0174 GMC make it go away permanently?

- Resetting the code may temporarily clear the warning light, but if the underlying issue causing the lean condition is not fixed, the code is likely to reappear during driving conditions.

10. Should I seek professional help to diagnose and repair OBDII code P0174 GMC?

- If you are unsure about diagnosing or repairing the issue yourself, it is advisable to seek professional help from a qualified mechanic to ensure the problem is properly identified and resolved.

Discuss the causes and fixes for P0174 GMC OBDII Code

  • 2000 gmc savanna 2500 5.7 have had the intake gaskets replaced new plugs and wires ran good for a week now acts like it has a miss and were getting 4 codes po121,po161,p0174,p1345 any ideas

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    Only the P0161 code could be related to the the P0174. You should start by inspecting the sensor connector and the intake gasket installation

  • my name is jim I have a 2000 gmc Yukon 5.3 vortec engine it is also 4x4 the engine codes that are coming up are po171 and po174 both at the same time I clear these codes and these codes come back within a day or so????????

  • Unfortunately there are a few things that could cause the P0171 and P0174, but should not be related to the 4x4 system.

    Common problems for the P0171 and P0174 are:
    - Intake leaks (broken hoses or gasket)
    - Clogged injectors ( you could try using a fuel injector cleaner or/and high octane gas)

  • Hola yo tengo una 2002 GMC sierra y empezó a fallar y saco el código po300 y po174 y las bujías del lado del pasajero las llena de humo y también los sensores de oxígeno del ado del pasajero que me aconsejan

  • El problem mas comun cuando se tienen los dos codigos es el "Intake Manifold Gasket". Tambien este seguro que el filtro de aire y de gas esta limpios.

  • Gmc acadia slt awd se quiere apagar en baja cuando detengo el vehículo y el ralenti se pone inestable