P0134 on Toyota
O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 1)
P0134 on Toyota vehicles indicates o2 sensor circuit no activity detected (bank 1, sensor 1). Au7o has documented this code across 1 Toyota model — most commonly on RAV4. The PCM detects no detectable signal activity (the voltage stays flat) from the Bank 1, Sensor 1 upstream O2 sensor, indicating the sensor is not switching — often a dead sensor or open circuit. Typical repair costs on Toyota range from $120 to $400, depending on the specific model and root cause.
Common Causes of P0134
- •Failed upstream O2 sensor
- •Open signal or ground circuit
- •Blown sensor heater preventing operation
- •Disconnected connector
- •Exhaust leak preventing proper readings
P0134 on Toyota by Model
Toyota RAV4(1 issue)
- Upstream Air/Fuel Ratio Sensor Failure (Check Engine Light)2001-2010
The upstream (Bank 1 Sensor 1) wide-range air/fuel ratio sensor is a common high-mileage failure on 2001-2010 RAV4 four-cylinders. The heater element or sensing element degrades, setting codes such as P0125, P0134, P2195 or a heater-circuit code, and illuminating the check engine light. A failing A/F sensor causes poor fuel control, reduced economy, hesitation and can eventually contribute to a lean/rich condition and catalyst codes.
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View P0134 across all makes →Frequently Asked Questions
What does P0134 mean on Toyota?▼
P0134 stands for "O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 1)." The PCM detects no detectable signal activity (the voltage stays flat) from the Bank 1, Sensor 1 upstream O2 sensor, indicating the sensor is not switching — often a dead sensor or open circuit. On Toyota specifically, this code is documented across 1 model.
What causes P0134 on Toyota vehicles?▼
Common causes on Toyota: Failed upstream O2 sensor, Open signal or ground circuit, Blown sensor heater preventing operation, Disconnected connector, Exhaust leak preventing proper readings. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0134 on a Toyota?▼
Repair costs on Toyota range from $120 to $400, depending on the specific model and root cause.
Which Toyota models have P0134 documented?▼
Au7o has documented P0134 on 1 Toyota model: RAV4.