check engine light on 2005 Nissan Sentra

my check engine light came on and stayed on, i took it to the dealer and had it checked, they said that i had a faulty air fuel senor, i haven't had it fixed yet but now the check engine light is no longer coming on. it comes on when i start the car as usual, but then goes right off like it's suppose to do

by in Portsmouth, VA on February 06, 2010
1 answer
ANSWER by , February 06, 2010
They probably erased the code that was in the computer, this will turn off the light. If the light comes back on, and the diagnosis is correct, then you will have to replace the sensor. Has your fuel mileage been affected?