Live Manual
Engine Error

P0143

O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)

Severity
Low

Symptoms

Check engine light on, minor exhaust smell

Common Causes

  • Short to ground in sensor 3 signal wire
  • Defective Bank 1 Sensor 3 O2 sensor
  • Exhaust leak upstream of sensor
  • Failing catalytic converter

How to Fix

  1. 1 Repair grounded wiring
  2. 2 Replace the O2 sensor
  3. 3 Fix exhaust manifold or pipe leaks
  4. 4 Inspect catalytic converter
Estimated Repair Cost USD
$100 $350

Wiring repair: $100; O2 sensor: $150 - $350