Q: Error codes, engine light on

asked by on August 01, 2016

I took the car to the shop and after reading the codes, the car got two error codes. These were: P0140, indicating that the O2 sensor circuit has no activity, Bank 1, and P0171, indicating that the system is too lean, Bank 1. Also, the dashboard shows the engine light on. What does this mean and what should I check and fix?

Oxygen Sensor Replacement $108.80 - $869.59 Get a Quote
Fuel Injector Replacement $379.42 - $3631.88 Get a Quote
Check Engine Light is on Inspection $79.99 - $89.99 Get a Quote

Hello there. When these codes are seen together, it points to a malfunction in the oxygen sensor bank 1 circuit. This could be caused by many things such as a failing oxygen sensor, leaking fuel injector, rich or lean conditions, or wiring issues. Generally the oxygen sensor codes can cause either a lean or rich condition as the car’s computer attempts to adapt without proper oxygen sensor readings. I recommend having a qualified technician, such as one from YourMechanic, diagnose the Check Engine Light and perform any repairs required.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

Check engine light comes on intermittently

If the Check Engine Light is coming on then it would have set a code. The code may have been read, but a problem is not found or the mechanic could not find the problem. I would need to know...

My Check Engine Light is on and my engine misfires

Hello there. Many common faults could cause your vehicle to have a cylinder #2 misfire. The most common faults are the spark plugs, spark plug wires, coil, fuel injector, a vacuum leak, or low compression in the #2 cylinder. Given...

My car is leaking, jerky, and the battery and engine light came on after making a weird noise.

Green fluid sounds like engine coolant leaking. Overheating would seem to justify it being coolant. The battery and Check Engine Lights coming on may indicate that leaking coolant may have sprayed onto other components like the alternator or possible the...

Stabitrak came on

I would recommend having an engine diagnostic performed on your vehicle by a qualified technician. This inspection would start by determining what trouble codes have been stored in the vehicle's PCM. Once these trouble codes are determined the repair procedure...

Loss of power steering at random times?

Hello. We'll be happy to answer your question. The recall that you have not completed is most likely while your power steering has an intermittent failure. In may of 2015 Ford announced the recall of an estimated 400,000 models; 2011...

P0300 and P0305. Pending: P0304, P0306, P0171, P0174, P2196, P2198

Hi there. The issue that maybe happening is the are fuel injectors that are not firing and there is a vacuum leak on the engine. Possible multiple sensors are not working causing the P2196 and P2198 codes to appear. For...

Why is my car overheating? 2011 Chevrolet Cruze

Hi. It sounds like there may be a problem with the radiator being clogged or just not operating properly. If the radiator is clogged or not operating properly, it will cause the car to overheat and the heat to blow...

Engine misfires and check engine light is always on

It’s always a good idea to pull over and turn off your vehicle when the check engine light is blinking. A blinking check engine light usually means there is a severe misfire in one or more of the cylinders. Most...

Engine light on. I have code p0013

Hi there. It is possible that the wrong oil was used or this can occur if a poor quality oil filter was installed. Most of the time though on this vehicle it is caused by a failure in one of...

Related articles

P2227 OBD-II Trouble Code: Barometric Pressure Circuit Range/Performance
P2227 trouble code definition Either the barometric pressure sensor is providing a reading that does not correspond to the parameters of the...
Symptoms of a Bad or Failing Air Injection Hose
Check your car's air injection hose for signs of damage. If there are idling issues or the Check Engine Light turns on, you may have to replace it.