AutoCodes – Ford – P1157 1998 Ford F150

P1157 1998 Ford F150 Code - Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean

Quick Answer

The Heated Oxygen Sensor 2 (HO2S2) (Downstream), after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Exhaust gas leaks, Faulty Heated Oxygen Sensor 2 (HO2S2) (Downstream) Bank 2, Heated Oxygen Sensor 2 Bank 2 harness is open or shorted. 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: P1157 1998 Ford F150 indicates Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean.
Common causes: Common causes include Exhaust gas leaks, Faulty Heated Oxygen Sensor 2 (HO2S2) (Downstream) Bank 2, Heated Oxygen Sensor 2 Bank 2 harness is open or shorted.
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 3,227

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 24, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1157 1998 Ford F150 Description

The Heated Oxygen Sensor 2 (HO2S2) (Downstream), after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air-fuel mixture (air-fuel ratio) must maintain near the ideal stoichiometric ratio. The HO2S2 output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Powertrain Control Module (PCM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S2 generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The PCM interprets Lean when the HO2S2 voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The PCM interprets Rich when the HO2S2 voltage is above 0.45 V. The P1157 code will set when the PCM detects that the HO2S2 signal is below the voltage of range for an extended period.

OBDII Code P1157 1998 Ford F150 - Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean - AutoCodes.com — P1157 1998 Ford F150 Code - Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean

What does this mean?

What are the Possible Causes of the DTC P1157 1998 Ford F150?

Exhaust gas leaks
Faulty Heated Oxygen Sensor 2 (HO2S2) (Downstream) Bank 2
Heated Oxygen Sensor 2 Bank 2 harness is open or shorted
Heated Oxygen Sensor 2 Bank 2 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors

How to Fix the DTC P1157 1998 Ford F150?

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 P1157 1998 Ford F150 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 P1157 1998 Ford F150 code?

Need more information on how to fix the P1157 1998 Ford F150 code? Get Access to Factory Service Manuals

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 P1157 1998 Ford F150 Code

1. What are common symptoms of OBDII code P1157 on a 1998 Ford F150?

Symptoms may include poor fuel economy, rough idling, hesitation during acceleration, and the illumination of the check engine light.

2. What does the OBDII code P1157 on a 1998 Ford F150 mean?

The code indicates a lack of activity from the heated oxygen sensor on Bank 2 Sensor 2, suggesting a lean air-fuel mixture.

3. What are some possible causes of OBDII code P1157 on a 1998 Ford F150?

Potential causes include a faulty oxygen sensor, vacuum leaks, exhaust leaks, issues with the fuel system, or a problem with the engine's air intake system.

4. How can I diagnose the issue causing OBDII code P1157 on a 1998 Ford F150?

Diagnosis typically involves inspecting the oxygen sensor, checking for leaks in the exhaust system, examining the air intake system, and testing the fuel system for proper operation.

5. Can I continue driving my 1998 Ford F150 with OBDII code P1157 active?

While the vehicle may still be drivable, it is recommended to address the underlying issue promptly to prevent potential damage to the engine or emissions system.

6. How can I repair OBDII code P1157 on a 1998 Ford F150?

Repair may involve replacing the faulty oxygen sensor, repairing any leaks in the exhaust or intake systems, addressing issues with the fuel system, or clearing any clogs in the air intake.

7. Is it possible to reset the check engine light after fixing OBDII code P1157 on a 1998 Ford F150?

Yes, the check engine light can be reset using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes.

8. Will fixing OBDII code P1157 on a 1998 Ford F150 improve fuel efficiency?

Addressing the underlying issue causing the code can lead to improved fuel efficiency by ensuring the engine operates at the correct air-fuel ratio.

9. How much does it typically cost to repair OBDII code P1157 on a 1998 Ford F150?

Costs can vary depending on the specific issue, but repairs for this code may range from $100 to $500, including parts and labor.

10. Can a DIY enthusiast fix OBDII code P1157 on a 1998 Ford F150?

Some aspects of the repair, such as replacing the oxygen sensor, may be manageable for DIY enthusiasts with the necessary tools and experience. However, more complex issues may require professional assistance.