Toyota Repair: Check Engine Light, oxygen sensor, camary

Question
My 99 Camary V6, 172,000 miles, has had the check engine light on for two years.  The car runs like a champ, but I have sent close to $900.00 dollars.  I have been to a local shop and to the dealership. Both time they through the codes found one to fix drive it 10 miles and I pick it up and pay the bill. Within the next 25 miles it comes back on.  I do not what to do next.  Pleae advise.

Answer
You have the right to take it back to the shoppe and request they find the problem. $900 dollars is quite a lot for a shoppe to "Guess" at. In my opinion, it has to do with an Oxygen sensor. Since the car runs fine, I would guess it would be the last sensor in the exhaust line. Lastly, make sure you have the proper thermostat, if there is one even installed or not collapsed. If you car runs for a while, but never reached operating temperature, the gas becomes rich and you exhaust will trigger the O2 sensor. I would suggest you take it back to the shoppe who charged you the $900 and ask them about this.