Fault code P0141 – a step-by-step guide to diagnosing and fixing it

DTC P0141 indicates that there is a problem with the oxygen sensor heater circuit on cylinder bank 1, downstream of the car's catalytic converter, such as a short or open circuit. The code is triggered when the control module determines that the sensor is taking too long to reach the right operating temperature, based on the temperature of the coolant. The signal from this device is used to monitor the efficiency of the catalytic converter.

• Damage to the wires or connectors causing an open circuit
• High resistance in the heating element
• A frayed or melted cable insulation sheath, resulting in a short circuit
• Loose or oxidised connectors causing a poor electrical connection
• A rich air-fuel mixture, bad timing or worn piston and cylinder parts causing carbon deposits and contaminants to accumulate around the sensor

• A reduction in fuel efficiency due to an underperforming lambda probe
• Activation of the check engine light
• A rough idle, engine hesitation, or poor acceleration
• An increase in carbon deposits inside the engine and catalytic converter
• Strange smelling exhaust fumes
• A crackling sound coming from the catalytic converter (rare)

What you’ll need:

• An OBD2 scanner
• A multimeter
• Electrical contact cleaner spray

Checking and fixing the components:

• Connect the diagnostic scanner to the vehicle via the data link connector port and check the freeze frame data from when the DTC was triggered. Analysing the data should help you to identify the root cause of the malfunction.
• Check the power supply to the car oxygen sensor by testing the voltage. To do this, you will need to locate the device’s harness connector and follow the manufacturer’s testing instructions. This information should be specified in the vehicle’s repair manual. The voltage between the connector pins should be roughly 12V. If the voltage is too low or no voltage is detected, it may be because the wires need replacing.
• Remove traces of corrosion and dirt from the electrical connectors to restore their conductivity and the flow of electrical current.
• Measure the resistance of the heater circuit by connecting the multimeter. The readings should be compared to the standard values specified by the manufacturer in the repair manual. If there is an internal sensor fault, you will need to install a new component.