OBD Guide

P1157

Air/Fuel Ratio Sensor 1 Range/Performance Problem

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