Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Powertrain Control Module (PCM) supplies about .45 volt to Oxygen Sensor 1 (O2S 1). The O2S 1 supplies a varying voltage from about one volt when exhaust is rich to about .10 volt when exhaust is lean. PCM monitors and stores sensor voltage information and evaluates the voltage samples to determine amount of time sensor voltage is out of range. If PCM detects O2S 1 voltage remains at or about .45 volt for an extended period, DTC P0134 will set.
For duplication of DTC, ensure:
- DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0171, P0200, P0300, P0301, P0302, P0303, P0304, P0335, P0440, P0442, P0446, P0506, P0507, P0601, P0602 or P1441 are not set.
- Airflow is greater than 3 gm/s.
- ECT is greater than 158°F (70°C).
- TP sensor angle is 4-56 percent for 20 seconds.
- Engine run time is greater than 30 seconds.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.