P0141 OBD2 Trouble Code – Check that rear O2 Sensor!

Meaning of P0141 Generic OBD2 Code

The technical definition of a P0141 generic OBDII code is: O2 Sensor Heater Circuit Malfunction in Bank 1 Sensor 2

This trouble code has something to do with the heater circuit in O2 sensor #2 in bank 1. It means the heater circuit is taking too long to enter closed loop mode. When this occurs, the ECU will trigger a check engine light and P0141 code. Very similar to the P0135 code, just the rear O2 sensor rather than the front.

The heating circuit in the oxygen sensor is responsible for giving accurate readings when the O2 sensor is cold. Once the engine warms up, the O2 sensor should revert to closed loop mode. If the ECU detects the coolant is within the desired operating temperature and the #2 O2 sensor is still not measuring the oxygen content of the exhaust, the P0141 generic code is generated.

Unless you’re an experienced mechanic who knows exactly what he’s doing (in which case why are you reading this??) then go ahead and watch this 30 minute video from EricTheCarGuy. He does an awesome step-by-step guide to troubleshooting the O2 sensor causing this DTC.

What are the causes of P0141 OBD-II Code?

In most cases, a P0141 code means a faulty or worn out oxygen sensor. It also means high resistance in the heater circuit or an open circuit in the heater element.

And while most people blame a faulty catalytic converter for a P0141 DTC, it is always best to first check the wiring and the O2 sensor before ruling out a failed catalyst.

The good news is the code can also be triggered by a frayed or shorted wiring harness. Since the P0141 code has something to do with oxygen sensor #2 (which is critically located behind the catalyst), the wiring can succumb to extremely high temperatures. Broken or loose connectors can also cause the ECU to trigger a check engine light.

What are the symptoms of P0141 DTC?

Since the engine is constantly operating in closed loop mode, this fault will cause the motor to run excessively rich, even if the motor is sufficiently warmed up. This can cause rough idling, poor acceleration, or hesitation upon steeping on the gas pedal.

And if you know anything about cars, an engine that is running a rich mixture has a tendency to accumulate a fair share of carbon deposits in the combustion chamber. This leads to early deterioration of spark plugs and other engine components.

Of course, the main symptom of a P0141 code is the presence of a check engine light in the console.

How much does it cost to fix P0141 Fault?

In most cases, the problem can be fixed by replacing the O2 sensor.

But before you do that, it is important to rule out other causes like oil or coolant leaks in the exhaust, physical damage on the O2 sensor, or shorted wiring. Of course, you can expect to pay less if the trouble code is triggered by an electrical or wiring problem.

Replacing the O2 sensor will only cost $25 to $50 for most vehicles. If the problem is traced to fluid or exhaust leaks, the repair bill can easily reach hundreds to thousands of dollars.

-Mike