Hi, I have a 1997 C 280. Recently the engine light has gone on. I know this has something to do with the pollution control. I had it checked out and the mechanic said that the gas cap may not be creating a sufficient seal. He suggested that I buy a new gas cap. He reset the light and it stayed off for a couple of days but it is now on again.
Has anyone had this happen. The car is running great. It doesn't seem like there is any problem.

Thanks
Karen

 

Bad oxygen sensor. Any Benz mechanic knows it. You must have talked to a gas station mechanic.

Read OBD2 code and it will tell you which O2 sensor has gone bad.

Your car I6 or V6? (V6s have 4 O2 sensors. Left and Right, Before and After.)

 

Thanks...I will have it checked out. My car is a V6

 

obviously fly_major is not a benz mechanic. there are hundreds of things that will set off the check engine light and every one of them is emissions related. especially on the 112 motor which is what should be in your vehicle since u said it was a v6 not inline. a bad air pump or switchover valve will make a good o2 sensor fail the systems self test and make it seem its an o2 sensor. i would at least have the dealer give you a print out of the codes then start researching possibilities. otherwise u might end up with a bunch of new parts and wasting alot of money