So i bought a 01 sentra 44k miles for my first car. Driving it daily my Check
Engine light came on. So i took it to a friend of a friend mechanic and the code read oxygen sensor. Got them replaced etc. Driving it more the CEL came on again and i got the code read at an advanced auto parts. The code came up oxy sensor again. Took it back to the mechanic and he said it must be time for 50k maintenence. So he replaced the spark plugs (car startup is much cleaner now) and he cleaned the fuel injectors becuase he said 2 of them were dripping. He assured me 210 dollars later that the CEL would not come back on and he even drove it around to make sure. Now the car doesnt seem to drive any different minus startup and the gas mileage seems the same (should be better after new plugs and cleaned injectors). But one thing i really noticed is when i start the electronics in the car all the lights come on to be sure they are working but the CEL does not come on before the startup. Is there anyway he could have disabled it or something to assure it would not come back on and possibly have not done any quality work at all?


Sorry for the wall of text, i joined this forum because im obsessed with audis and german engineering but i cant afford one (poor college student). This is my first car and any help would be appreciated. Thanks.