Engine-Codes - Generic - P1157

P1157 - Air/Fuel Ratio Sensor 1 Range/Performance Problem

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3  What is this?
Table of contents

P1157 Possible Causes

  • Faulty Air/Fuel Ratio Sensor 1
  • Air/Fuel Ratio Sensor 1 harness is open or shorted
  • Air/Fuel Ratio Sensor 1 circuit poor electrical connection

How is the P1157 code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the P1157 code

Labor: 1.0

The cost to diagnose the P1157 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
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Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1157 Meaning

The Air/Fuel Ratio (A/F) sensor 1 is installed in the exhaust system and detects oxygen content in the exhaust gas. The A/F sensor transmits output voltage to the Engine Control Module (ECM). A heater for the sensor element is embedded in the A/F sensor (sensor 1). It is activated and heats the sensor to stabilize and speed the detection of oxygen content by controlling current flowing through the heater. An increase in the current levels off as the applied voltage to the element electrode reaches a certain range because the amount of oxygen which is led through the diffusion layer is limited. The current amperage is proportional to oxygen content in the exhaust gas, so the air/fuel ratio is detected by the measurement of the current amperage. The ECM compares a set target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.
If the A/F sensor (sensor 1) voltage is low, the air/fuel ratio is lean, and the ECM uses A/F feedback control to issue a Rich command. If the A/F sensor (sensor 1) voltage is high, the air/fuel ratio is rich, and the ECM uses A/F feedback control to issue a Lean command.

More Information

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Information for specific makes

  • P1157 ACURA Air/Fuel Ratio Sensor 1 Range/Performance Problem
  • P1157 AUDI Manifold Absolute Pressure Sensor Supply Voltage
  • P1157 BMW O2 Sensor Heater Circuit High Voltage Bank 2 Sensor 2
  • P1157 BUICK HO2S Bank 2 Sensor 2 Lean System Or Low Voltage
  • P1157 CADILLAC HO2S Bank 2 Sensor 2 Lean System Or Low Voltage
  • P1157 CHEVROLET HO2S Bank 2 Sensor 2 Lean System Or Low Voltage
  • P1157 FORD Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean  
  • P1157 GMC HO2S Bank 2 Sensor 2 Lean System Or Low Voltage
  • P1157 HONDA Air/Fuel Ratio Sensor 1 Range/Performance Problem  
  • P1157 LINCOLN Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean  
  • P1157 MAZDA HO2S-12 Circuit Condition
  • P1157 MERCURY Lack Of Heated Oxygen Sensor Switches Bank 2 Sensor 2 Indicates Lean  
  • P1157 MINI O2 Sensor Heater Circuit High Voltage Bank 2 Sensor 2
  • P1157 VOLKSWAGEN Manifold Absolute Pressure Sensor Supply Voltage

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