I have an ongoing intermittent problem with the check engine light coming on, and was told that it is due to a bad oxygen sensor. I will come on for a few days or a week and go out. This has gone on for about a year. My mechanic said it is not a cheap to fix mostly due to cost of labor. I would like to see if I can locate parts and do it myself, or if this is something better left to the experts. Any assistance would be greatly appreciated.