I have a '95 with 140,000 miles; check engine light came on for first time ever; went to mechanic for diagnostic; told it was a knock sensor " and "an egr valve.
Wouldn't it be one or the other that would set the light off?. Could I do any major damage to my car by driving it under these conditions

 

not sure about the egr prob, but you can drive with a bad knock sensor youll just be slower than molasis running uphill in alaska