Hi, all I got a lot of kind responses after I posted my original questions regarding to CAT+O2 sensor. I feel such relief after reading your responses. So far, the engine check light is still off and I am anxious to see what will happen next. I have some more questions after reading your responses:
- Is it possible that I pumped some "bad" gas that caused the whole problem? I keep pumping the cheapest gas I can find and never stick to the brand
- How could dealer's mechanic tell the internal worn of CAT? Can such internal worn be detected virtually without taking down the CAT?
- I am thinking about purchasing an OBD II scanner. If check engine light is not on, Can I still use it to do some kind of early detection of my car, e.g., whether the car will pass emission test, etc?
Thanks.