Vehicle: Mazda 626 2001. The engine light has kicked on numerous times while driving at a 35-40mph. Mechanics indicate that the code references the one of two problems- oxygen sensor defect or catalyst inefficiency. But, because the code is not specific as to which piece is defective the only recourse is to drive the vehicle and if the engine light turns off don't worry or bring the vehicle back if the light continues to stay on. I have continued to drive the vehicle and of course the light turns itself off. I return to the service station when the light turns back on. This problem has been occurring over a two month time span. I have not had any work done to "solve" the problem because no one knows what the problem may be. This is not a valid answer. The engine light would not activate if there is "no problem". please provide assistance. If you are having this problem please file a complaint.

- Lexington, KY, USA