OBD Guide

P1131

Lack Of HO2S Switch - Sensor Indicates Lean

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–61 (est.)

Symptoms

  • Increased fuel consumption
  • Unstable engine idling
  • Power Loss
  • Check Engine light comes on

Causes

  • Oxygen sensor malfunction
  • Air leaks in the intake tract
  • Problems with the fuel pump or injectors
  • DMRV malfunction
  • Damage to sensor wiring

How to Fix

  1. Check the tightness of the intake tract
  2. Check the operation of the fuel system
  3. Check the condition of the oxygen sensor and its wiring
  4. Replace a faulty oxygen sensor
  5. Reset the error code and check if it returns

Related codes

Error P1131 by Vehicle Brand