AutoCodes – MINI – P0174 MINI

P0174 MINI Code - Mixture Control 2 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 MINI indicates Mixture Control 2 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 2,349

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 MINI 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 MINI - Mixture Control 2 System Too Lean Bank 2 - AutoCodes.com — P0174 MINI Code - Mixture Control 2 System Too Lean Bank 2

What does this mean?

What are the Possible Causes of the DTC P0174 MINI?

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 MINI?

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 MINI 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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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 MINI Code

What does the OBDII code P0174 indicate on a MINI?

Code P0174 indicates that the engine control module (ECM) has detected that the fuel mixture is too lean (too much air, not enough fuel) on Bank 2 of the engine.

What are common symptoms of code P0174 in a MINI?

Symptoms of code P0174 may include a rough idle, hesitation or stumbling during acceleration, reduced fuel efficiency, and a check engine light that is illuminated.

What might cause a MINI to display the P0174 code?

Possible causes for the P0174 code in a MINI include a vacuum leak, faulty or dirty mass air flow (MAF) sensor, weak fuel pump, clogged or dirty fuel injectors, or a malfunctioning oxygen sensor.

How can I diagnose the cause of a P0174 code in a MINI?

To diagnose the P0174 code, start by checking for any additional codes that could indicate a specific component failure. Inspect for vacuum leaks, test the MAF sensor, and check the condition of the fuel injectors and fuel pump. Also, inspect the oxygen sensors for proper operation.

What steps can be taken to repair the P0174 code on a MINI?

Repairing the P0174 code may involve replacing or cleaning the MAF sensor, repairing any vacuum leaks, replacing faulty oxygen sensors, cleaning or replacing clogged fuel injectors, or replacing the fuel pump if it is found to be weak.

Is it safe to drive a MINI with the P0174 code?

While you can technically still drive your MINI with the P0174 code, it is advisable to address the issue as soon as possible. Driving with a lean mixture can lead to engine damage over time, such as overheating or increased wear on engine components.

Can a dirty air filter cause the P0174 code to appear on a MINI?

Yes, a dirty air filter can restrict air flow to the engine, affecting the air-fuel mixture and potentially triggering the P0174 code. Replacing a dirty air filter is a simple and cost-effective first step in troubleshooting this issue.

How does a faulty oxygen sensor lead to the P0174 code in a MINI?

A faulty oxygen sensor can send incorrect data to the engine's computer, indicating that the air-fuel mixture is leaner or richer than it actually is. This misinformation can cause the computer to adjust the mixture incorrectly, leading to the P0174 code.

What is the difference between Bank 1 and Bank 2 concerning the P0174 code?

In a V-shaped engine, Bank 1 refers to the side of the engine where the first cylinder is located, while Bank 2 is the opposite side. The P0174 code specifically refers to a lean condition detected in Bank 2.