I just replaced my 02 sensor. Light went off right away. But came back on 2 days later. If I turn off my car and restart it. It goes away again for 4-5 day then back on again. Whats going on?
Second. My oil light does the same thing it comes on and starts blinking. If I shut the car off and then restart it it goes away for a week then back on.
Is it my oil sending unit going bad or what?

 

I have a Helm manual; yes it says to check/replace sending unit for your Oil light issue.

now you already replaced the O2 sensor, I think time to check your pcv valve too. then reset the ECU. you should be Ok unless some other issues with your car.

 

What code are you getting that led you to change the O2 sensor?

 

I checked the pcv, its still good. My car got only 54k miles on it. I did disconnect the battery to reset my ECU. But problem still stands.