P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)

Description and meaning of DTC p0134

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model. This code refers to the front oxygen sensor on Bank1. Basically the oxygen sensor is inactive. Here's why:The powertrain control module (PCM) provides a baseline voltage of about 450mV on the oxygen sensor signal circuit. When cold, the PCM detects the the internalresistance of the sensor is high. As the sensor warms up the resistance is loweredand it starts producing voltage based on the oxygen content in the exhaust. When the PCM determines that the time it took for the sensor to warm up is greaterthan one minute or that the voltage is inactive (not reading outside 391-491mV it views the sensor as inactive or open and sets the P0134 code.

p0134 diagnostic trouble code symptoms

One or more of the following may occur:Check engine light illuminationPoorly running/engine missingBlowing black smokePoor fuel economyDying, stuttering

DTC p0134 - possible causes

A code P0134 may mean that one or more of the following has happened:Bad O2 (oxygen) sensorBad heater circuit in the O2 sensorWiring or connector to the sensor frayed / brokenBlown heater circuit fuseHoles in the exhaust systemPCM failure

How to fix OBD-II diagnostic trouble code p0134

The most common fix is to replace the oxygen sensor. But that doesn't ruleout the possibility of:Rusted exhaust pipeInspect wiring connector(s) for problemsExcessive amperage blowing heater fuse (still requires replacement of sensorbut also replacement of blown fuse)Replace PCM (only as last resort after all other possibilities are covered.

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