AutoCodes – Honda – P0174 Honda

P0174 Honda Code - Fuel System Too Lean Bank 2

Quick Answer

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring. 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 Honda indicates Fuel System Too Lean Bank 2.
Common causes: Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring.
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 36,856

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 Jun 14, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0174 Honda Description

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).

OBDII Code P0174 Honda - Fuel System Too Lean Bank 2 - AutoCodes.com — P0174 Honda Code - Fuel System Too Lean Bank 2

What does this mean?

What are the Possible Causes of the DTC P0174 Honda?

Intake air leaks
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Air Flow (MAF) sensor
Incorrect Positive Crankcase Ventilation (PCV) hose connection

How to Fix the DTC P0174 Honda?

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 does this mean?

Code Tech Notes

If the P0171 is combined with the P0174 code, it's very 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 air flow meter. If the problem persists the front oxygen (O2) sensor may need to be replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0174 Honda 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.

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Need more information on how to fix the P0174 Honda code? Get Access to Factory Service Manuals

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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 P0174 Honda Code

1. What are the common symptoms of OBDII code P0174 (Fuel System Too Lean Bank 2) in a Honda?

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

2. What are the possible causes of OBDII code P0174 in a Honda?

- Potential causes may include a vacuum leak, faulty oxygen sensor, clogged fuel injectors, a malfunctioning mass airflow sensor, or a problem with the fuel pressure regulator.

3. How can I diagnose the OBDII code P0174 in my Honda?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, checking for any visible signs of damage or leaks in the air intake system, inspecting the oxygen sensor, and performing a fuel pressure test.

4. What are some DIY repair tips for fixing OBDII code P0174 in a Honda?

- DIY repair tips may include checking and replacing damaged vacuum hoses, cleaning or replacing the oxygen sensor, inspecting and cleaning the mass airflow sensor, and ensuring the fuel pressure regulator is functioning correctly.

5. Is it safe to continue driving my Honda with OBDII code P0174 (Fuel System Too Lean Bank 2)?

- It is not recommended to drive your vehicle for an extended period with this code as it can lead to potential engine damage or further issues with the fuel system. It's best to address the problem promptly.

6. Can a clogged fuel filter cause OBDII code P0174 in a Honda?

- Yes, a clogged fuel filter can restrict fuel flow, leading to a lean fuel mixture and triggering the OBDII code P0174 in a Honda.

7. Will resetting the check engine light resolve OBDII code P0174 in my Honda?

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

8. How much does it typically cost to repair OBDII code P0174 in a Honda at a professional mechanic?

- The cost of repairing this code can vary depending on the specific cause and parts needed. It's recommended to consult with a mechanic for an accurate diagnosis and cost estimate.

9. Can a faulty catalytic converter trigger OBDII code P0174 in a Honda?

- Yes, a failing catalytic converter can cause improper fuel combustion, leading to a lean fuel mixture and triggering the OBDII code P0174 in a Honda.

10. How long does it usually take to repair OBDII code P0174 in a Honda?

- The repair time can vary based on the cause of the issue and the extent of the repairs needed. It may take anywhere from a few hours to a full day, depending on the complexity of the repair.