Honda Civic P0141: Oxygen Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

Quick Answer: What is P0141?

On a Honda Civic, the P0141 code means the internal heating element in the Downstream Oxygen Sensor (Sensor 2) has failed. Sensors need to be hot to work correctly; if the heater is broken, the sensor won't read emissions accurately until the car has been driven for a long time.

Severity: LOW. The car will drive normally, but you will fail state emissions inspections. It may also lead to a slight decrease in fuel economy because the engine stays in "open-loop" mode longer than it should.

Common Symptoms

Check Engine Light: Illuminated with code P0141.
Failed Smog Check: The vehicle will not pass emissions testing.
Slightly Higher Fuel Consumption: The computer cannot fine-tune the fuel mixture as quickly.
No Driving Issues: Usually, there are no noticeable engine stumbles or hesitations.

Most Likely Causes

Faulty O2 Sensor (90%): The internal heating coil inside the sensor has burnt out or "opened."
Blown Fuse: A short in the sensor can blow the fuse that powers the heater circuit.
Damaged Wiring: On lowered Civics, the harness for the rear O2 sensor can get caught or scraped by road debris.
Loose Connector: Corrosion or moisture in the sensor plug.

Detailed Repair Cost Breakdown

Estimates for Honda Civic in the US market:

Component / Task	Aftermarket Part	OEM Denso/Honda Part	Labor Time
Downstream O2 Sensor (Sensor 2)	$50 - $90	$180 - $260	0.5 - 1.0 hr
Fuse Replacement	$5	$10	0.1 hr

How to Fix P0141 on a Honda Civic

1. Check the EVAP/O2 Fuse

Before buying a sensor, check the fuse box. In many Civics, the O2 sensor heater circuit shares a fuse with other components. If the fuse is blown, the new sensor won't work either. Replace any blown fuses and see if the code returns.

2. Inspect the Wiring Harness

The downstream sensor is located after the catalytic converter, underneath the car. Inspect the wires leading to the sensor for any signs of melting, fraying, or scraping against the pavement (common on lowered Civics). If the wires are damaged, you can often solder them or simply replace the sensor.

3. Always Use Denso or NTK

Honda vehicles are notoriously picky about sensor brands. Only use Denso or NTK sensors. Using "universal" or cheap store-brand sensors often triggers a secondary Check Engine Light because the resistance levels aren't perfect. It is worth the extra $40 for the original manufacturer part.