P0134 - O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
Oxygen sensors are used to measure the Oxygen content in the exhaust system. The ECM can use this information to monitor and adjust the air / fuel ratio and to check on catalytic converter efficiency
Fault Code Explained
The ECM has detected that the sensor output is at a constant value with no changes in the output signal
Oxygen sensor related fault codes will often be set due to other engine faults and when testing care should be taken to ensure that there are no other fueling, ignition or misfire faults on the vehicle that are causing an Oxygen sensor fault to be stored.
There are different wiring configurations depending on the type of Oxygen sensor fitted, recommended tests include:
- Test sensor output signal under varying loads
- Test wiring between sensor and ECM