OBD Guide

P1157

Air/Fuel Ratio Sensor 1 Range/Performance Problem

P1157 is an OBD-II diagnostic trouble code meaning: Air/Fuel Ratio Sensor 1 Range/Performance Problem. Common causes: air/fuel ratio sensor malfunction, damaged or corroded sensor wiring. Estimated repair cost: $33–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$33–89 (est.)

Symptoms

  • Unstable engine operation at idle
  • Increased fuel consumption
  • Reduced engine power
  • Check Engine Light Is On
  • Dips during acceleration

Causes

  • Air/fuel ratio sensor malfunction
  • Damaged or corroded sensor wiring
  • Vacuum leaks in the intake manifold
  • Problems with the fuel system (injectors, fuel pump)
  • Sensor contamination due to the use of low-quality fuel

How to Fix

  1. Check the integrity of the sensor wiring and connectors
  2. Clean the sensor contacts from corrosion
  3. Check for vacuum leaks
  4. Replace air/fuel ratio sensor if necessary
  5. Check the operation of the fuel system

Related codes

Error P1157 by Vehicle Brand

FAQ

What does the P1157 code mean?

P1157 is an OBD-II diagnostic trouble code that indicates: Air/Fuel Ratio Sensor 1 Range/Performance Problem

What causes a P1157 error code?

The most common causes of P1157 include: Air/fuel ratio sensor malfunction; Damaged or corroded sensor wiring; Vacuum leaks in the intake manifold; Problems with the fuel system (injectors, fuel pump).

How do I fix a P1157 diagnostic trouble code?

To fix P1157: Check the integrity of the sensor wiring and connectors. Clean the sensor contacts from corrosion. Check for vacuum leaks. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1157?

Yes, but get it checked soon

How much does it cost to fix P1157?

The estimated repair cost for P1157 is $33–89. Actual cost depends on your vehicle, location, and labor rates.

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