Poor fuel mileage.
Yes, a faulty O2 sensor will cause the check engine light to come on. Many auto parts stores will plug in an ODBII code reader to your Expedition to get the "trouble code" that tells you which sensor (there are 4) is faulty, free of charge.
The check engine light will illuminate. The code(s) will direct you to the faulty sensor.
The most common causes of check engine light malfunction are a faulty oxygen sensor, loose or faulty gas cap, or a faulty catalytic converter. These are all easily fixed problems.
Replace the faulty speed sensor and the light will reset itself after a short drive.
Faulty sensor get it replaced if not check to make sure wire isn't shorting out
The check engine light will illuminate if you have a bad O2 sensor. The code set will lead you to the faulty sensor.
* It could be a faulty check engine light or a light sensor problem . There's probably not a problem with the engine at all just the faulty sensor light problem most likely. * ----------------------------------------------------------------------------------------------------If your check engine light stays on with the engine running , a malfunction with the emission control system has been detected. Have your vehicle scanned for any trouble codes in order to diagnose and repair the problem. ( I had a check engine light come on at 35000 miles - in my case it turned out to be the DPFE sensor )
if you disconnect the o2 sensor cable in the air intake then start the engine you would see the check engine sign turned on in the gauge panel. It is on then the sensor is working if off the the sensor may have problems
how do i know if the o2 sensor is bad. The check engine light would illuminate and the code(s) set would steer you to the faulty O2 sensor.
Check Engine light is on. Engine OK when cold, but when reaches operating temperature it stalls at idle.
The "Check Engine" light will illuminate when the ECM (engine control module) receives a signal from a sensor that is out of its parameter. It could be a faulty sensor or the sensor may be doing its job reporting a problem to the ECM.
Your Mass Air Flow Sensor (MAFS) is faulty. Check with your local Nissan dealer.