How do you replace the oxygen sensor on a 2003 Toyota Matrix?
Find very good instructions with photos at:
I used them and they are easy to follow. Replacement time 15 minutes.
The oxygen sensor is in the factory manifold coming off of the front of the engine. It has been a while since I looked at mine but I think it is the only plug in wire on the exhaust.Get a new sensor and go to a local muffler shop and they will do it in no time, or pull it out yourself and plug in the new one.