P1129
Downstream Oxygen Sensors Swapped from Bank to Bank
Severity
⚠️ MediumCan you drive?
Yes, but get it checked soon
Approx. repair cost
$22–56 (est.)
Symptoms
- Unstable engine operation
- Increased fuel consumption
- Increased emissions
- Check Engine Light Is On
Causes
- Incorrect connection of oxygen sensors after repair
- Wiring damage
- Error when replacing sensors
- Engine control unit malfunction
How to Fix
- Check that the oxygen sensors are connected correctly
- Inspect the wiring for damage
- Check the operation of oxygen sensors
- Replace sensors if necessary