P0021 2002 Nissan Altima Sedan -

Question

Does this need to be done in order to pass state inspection? This engine is notorious for consuming oil. the engine light came on as it has many times in the past. It has always been: low oil. I usually add oil and a short time later the light goes out but not this time. Do I need a new oxygen sensor to correct the problem? I need to get the car inspected asap!

Thank you,
Gary

Answer 1

This problem is not related to the oxygen sensor. 

P0021 Nissan - Intake Valve Timing Control Performance Bank 2 

Since the Intake valve timing control solenoid valve uses oil flow to control timing, dirty oil can cause the valve to stuck open or close. Before replacing the valve, change engine oil and filter and reset engine code.

Low oil is your problem, you need 5 quarts of oil in your the car, you probably have less than 4 quarts (if not less) if there light it coming on.