Disconnecting Battery to clear bad oxygen sensor and catalytic converter?

I am trading in my car and the check engine light is on because I need a new catalytic converter and oxygen sensor. If I disconnect the battery and clear the code, how far do you think I will be able to drive without the light reappearing?|||Depending on the car, disconnecting the battery will likely not clear the code at all. Most OBDII cars store emissions faults.





If you did clear the code, it would likely come back relatively quickly, either a failed O2 sensor or a failed catalytic converter is going to get picked up very quickly. My guess is maximally you'll have 10 minutes, or 5 restarts.





The dealership is likely going to have to emissions test it for re-sale anyway, and they're going to discover this. I would suggest just turning it in with the light on, it shouldn't be that big of a problem.





I also think it unlikely to have both a failed catalytic converter and O2 sensor, the catalytic converter failing would signal the O2 sensor, the O2 sensor failing would mean nothing else.





At the end of the day we're talking about $30-$60 for most O2 sensors, $100-150 for a catalytic converter, and 1 hour of labor. The dealership really shouldn't care, as they have to invest more on average in preparing a car for sale.|||It depends on your car's computer.





I know in my Ford Escape, because I don't have the money to buy new catalytic converters at the moment, I've been resetting the computer, and I can usually get about 400 miles without the light coming on.|||Depends on how bad it is. Disconnecting the battery will not work though because of a capacitor in the computer. If you take the cables off and touch the lead ends together for about 10 minutes it will drain the capacitor and clear the codes until they set again which could be at anytime. AutoZone will clear the codes for free with a scanner though.