How to tell if my O2 sensor is bad?

[doug294]

How do I know if my O2 sensor is bad?

[Melt]

generally the check engine light would come on and your ECU would throw a code

[doug294]

my check engine light is one, but I don't know how to read the codes. Plus it doesn't stay on, it comes on after a few min, will it through the code when it comes on?

[90civicrider]

Just replace it anyway. O2 sensor should only be like 15-20 bucks. If thats not the problem then you still have a new O2 sensor that will last you years to come

[FourthGenHatch]

Usually your car will run very rich (you will get shitty gas mileage).

[i_a_n112784]

To see error codes, pull back the passangerside carpet, you should be able to pull it far enough without taking anything off/out. You should be able to see a small circle. It will have a red LED that will bink when the key is turned to ON. The ECU's have a memory so the engine light doesnt have to be on. The light will blink rapidly to represent the code. If there are more than one codes, it will blink the one, then pause, then blink the other.

One blink means O2 sensor