AutoCodes – Scion – P0171 2005 Scion xB

P0171 2005 Scion xB Code - Air/Fuel Mixture System Lean Bank 1

Quick Answer

The fuel trim is related to the feedback compensation value, not to the basic injection time. Common causes include Intake air leaks, EFI relay, Faulty front heated oxygen sensor. 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: P0171 2005 Scion xB indicates Air/Fuel Mixture System Lean Bank 1.
Common causes: Common causes include Intake air leaks, EFI relay, Faulty front heated oxygen sensor.
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 9,300

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 Jul 20, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0171 2005 Scion xB Description

The fuel trim is related to the feedback compensation value, not to the basic injection time. The fuel trim consists of both the short-term and long-term fuel trims. The short-term fuel trim is fuel compensation that is used to constantly maintain the air-fuel ratio at stoichiometric levels. The signal from the front Heated Oxygen (HO2) sensor indicates whether the air fuel ratio is rich or lean compared to the stoichiometric ratio. This triggers a reduction in the fuel injection volume if the air-fuel ratio is rich and an increase in the fuel injection volume if it is lean. Factors such as individual engine differences, wear over time and changes in operating environment cause short-term fuel trim to vary from the central value. The long-term fuel trim, which controls overall fuel compensation, compensates for long-term deviations in the fuel trim from the central value caused by the short-term fuel trim compensation.

OBDII Code P0171 2005 Scion xB - Air/Fuel Mixture System Lean Bank 1 - AutoCodes.com — P0171 2005 Scion xB Code - Air/Fuel Mixture System Lean Bank 1

What does this mean?

What are the Possible Causes of the DTC P0171 2005 Scion xB?

Intake air leaks
EFI relay
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
ECM

How to Fix the DTC P0171 2005 Scion xB?

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 P0171 2005 Scion xB 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 P0171 2005 Scion xB Code

1. What does OBDII code P0171 on a 2005 Scion xB mean?

- The code P0171 indicates that the engine control module has detected a lean condition in the air/fuel mixture on Bank 1 of the engine.

2. What are the common symptoms of a P0171 code in a 2005 Scion xB?

- Common symptoms include rough idling, poor acceleration, hesitation or stumbling during acceleration, and an illuminated check engine light.

3. What are the possible causes of a P0171 code in a 2005 Scion xB?

- Common causes include a vacuum leak, faulty oxygen sensor, clogged fuel filter, dirty or faulty mass airflow sensor, or issues with the fuel injectors.

4. How can I diagnose a P0171 code on a 2005 Scion xB?

- Diagnosing a P0171 code typically involves checking for vacuum leaks, inspecting the oxygen sensor, testing the mass airflow sensor, and ensuring proper fuel pressure.

5. Can a dirty air filter cause a P0171 code on a 2005 Scion xB?

- Yes, a dirty air filter can restrict airflow and lead to a lean condition, triggering the P0171 code.

6. How do I repair a P0171 code on a 2005 Scion xB?

- Repair methods may involve fixing vacuum leaks, replacing the oxygen sensor, cleaning or replacing the mass airflow sensor, changing the fuel filter, or addressing issues with the fuel injectors.

7. Is it safe to continue driving with a P0171 code on a 2005 Scion xB?

- It is generally not recommended to drive with a P0171 code as it can lead to poor engine performance and potential damage over time. It's best to address the issue promptly.

8. Will resetting the check engine light clear a P0171 code on a 2005 Scion xB?

- Resetting the check engine light may temporarily clear the code, but if the underlying issue causing the lean condition is not resolved, the code is likely to reappear.

9. Can a P0171 code on a 2005 Scion xB affect fuel efficiency?

- Yes, a P0171 code can negatively impact fuel efficiency as the engine may be running too lean, causing it to work harder and consume more fuel.

10. How can I prevent a P0171 code from recurring on my 2005 Scion xB?

- Regular maintenance, such as replacing air filters, checking for vacuum leaks, and using quality fuel, can help prevent a P0171 code from reoccurring.