OBD Guide

P1127

Exhaust Not Warm Enough, Downstream Sensor Not Tested

Severity
Low
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Check Engine light comes on
  • Minor changes in engine performance may occur
  • Reduced Emission Control System Effectiveness
  • Increased fuel consumption in some cases

Causes

  • Short trips without fully warming up the engine
  • Malfunction of the oxygen sensor heating element
  • Problems with wiring to the oxygen sensor
  • Low ambient temperature
  • Cooling system thermostat malfunction

How to Fix

  1. Check the condition of the oxygen sensor heating element
  2. Check the integrity of the wiring to the sensor
  3. Replace the oxygen sensor if necessary
  4. Check thermostat operation
  5. Drive for a long time to fully warm up the system.

Related codes

Error P1127 by Vehicle Brand