007

A while ago I had the CEL come on. It went away but the obd read the oxygen sensors were faulty. Since then the CEL has not come back on. So my question what would happen if you keep on driving without the replacing the sensors? Would you gas mileage decrease or should I should just replace them anyway? The car has 130k.

adv074

I believe that the computer just stored in memory that fault code even though the light turned off. Either way I am guessing that the sensor is in between specification (being in spec or out of spec) so basically it is on its way on going out. You can drive the car no problem, but slowly the fuel economy may go down and the CEL will stay on steady eventually. I would probably wait until the light is on permanently before replacing anything just to be sure that it is really that part causing the problems.

It was like that with my friend's CLK. Her CEL went on once and I scanned that it was the Mass air meter. I cleared it and a few days later it came on. It was doing that for about a couple of months and now it is on steady. Anyway now she has to replace it.