Code P0134 is triggered when your vehicle’s O2 sensor (bank 1, sensor 1) is malfunctioning. The Engine Control Module (ECM) detects that the Oxygen (O2) sensor is at a standstill and is not accurately reading the amount of oxygen in the exhaust.

What causes O2 sensor to have no activity?

If the O2 sensor isn’t reacting at all, it can be due to a dead sensor, a shorted or severed O2 signal wire, or, in some cases, it can be due to a bad O2 reference ground. Conventional O2 sensors have four wires: the two heater wires (one of which is grounded by the ECM/PCM to control the heater).

What causes O2 sensor code?

An engine misfire, leaky exhaust valve or a leak in the exhaust manifold gasket that allows air into the exhaust may also cause this type of code to be set. If an O2 sensor has failed, especially prematurely, the cause often is contamination. Like us, O2 sensors slow down as they age.