When replacing my old stock cat with a new high-flow Megan cat, the stock o2 sensor was rusted onto the body of the cat. So I had to get a new O2 sensor.

Instead of paying 70 bucks at advanced auto parts of pep boys, I paid 30 online for a generic O2 sensor.

I installed it, and afterwards the check engine light came on.

Hooked up the computer, cleared the codes, and the light came on again the second time I started up the car.

Either the wiring is off or this light will inevitably stay on regardless. Performance feels fine.

Looking to the civic gods for a little input.

 

What code is stored? If the light wasn't on before you replaced it then chances are you wired it wrong.