Emissions

P0141 — Oxygen Sensor Heater Circuit Fault (Bank 1, Sensor 2)

Severity: low Safe to drive

What P0141 means

The PCM monitors the heater circuit of the downstream oxygen sensor (bank 1, sensor 2) located after the catalytic converter. The heater brings the sensor to operating temperature quickly so it reads accurately even with cool exhaust. P0141 sets when heater current or resistance falls outside the expected range, due to an open, a short or a failed heating element.

Symptoms

  • Check Engine light on
  • Slightly higher fuel consumption
  • Failed emissions test
  • Emissions readiness monitors not complete
  • Possible P0420 if the sensor responds slowly
  • Rarely, an unstable idle

Possible causes

  1. Failed heater element in the oxygen sensor
  2. Open or shorted heater wiring
  3. Blown heater circuit fuse
  4. Poor or corroded connector contact
  5. Wiring damaged near the exhaust (chafed or heat-melted)
  6. Rarely, a faulty heater driver in the PCM

How to diagnose

  1. Scan for codes and freeze-frame data and note any catalyst or fuel trim codes
  2. Locate the bank 1 downstream sensor and inspect its wiring and connector for damage, melting and corrosion
  3. Check the oxygen sensor heater fuse per the vehicle wiring diagram
  4. Unplug the sensor and measure heater resistance, comparing it to the spec
  5. Check for power and the control signal or ground at the harness connector with ignition on
  6. Test the wires back to the PCM for opens and shorts to ground or power
  7. Look for exhaust leaks near the sensor and review live sensor data
  8. If wiring and heater are good, evaluate the PCM

Common fixes

  • Replace the bank 1 downstream oxygen sensor
  • Repair the wiring or connector
  • Replace the blown fuse after finding the cause
  • Reflash or replace the PCM if the driver fault is confirmed
  • Clear the code and verify it does not return

P0141 on different brands

Ford · manuals
On Ford, the extended format P0141:01 identifies the condition detected by the bank 1 oxygen sensor heater circuit monitor; it does not confirm a specific failed part.

Questions and answers

Can I drive with a P0141 code?

Usually yes for a short time. Don't delay the repair, since fuel use may rise and you may have trouble passing inspection.

What does bank 1 sensor 2 mean?

Bank 1 is the side of the engine with cylinder 1. Sensor 2 is downstream of the catalytic converter and checks its efficiency.

Do I always need a new sensor for P0141?

No. Check the fuse, wiring and connector first. Replace the sensor if its heater resistance is out of spec and the circuit is good.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.