Ford Repair: co2 sensor, oxygen sensor, auto parts store

Question
My 1997 Ford Expedition has been having problems. I stopped by an auto parts store and they read the computer code. They said it was P0133 which indicated a bad oxygen sensor. I would like to fix it myself if possible but cannot find any information about where the part is located, etc. Any help would be great!

Answer
P0133 indicates a slow response rate for the bank #1, sensor #1. I NEVER replace a sensor without confiming with further tests. The code does not specifically indicate the sensor is the problem, further testing is usually necessary to determine if in fact the sensor is slow or there is a wiring or PCM problem.

In your case the sensor is most likely slow. I probably do at least 2-3 of these a week. But I do not rely solely on the code for diagnosis, it is only a starting point. At the shop I have equipment than can help me determine the ACTUAL cause of a code.

The sensor indicated by your code is on bank #1, is located BEFORE the catalytic converter, in the exhaust pipe, usually near the exhaust  manifold. On Expeditions they can be very hard to access without proper tooling.