My O2 sensor diagnosis
- Had car diagnosed at auto zone for free because the eng ck light came on. They said it was o2 sensor or MAP sensor per the codes. My wife actually took the car to Auto Zone since she works within 1/10 mile of the place. She wrote down the codes but forgot where she put the notes.
- I went back to the same place about 4 weeks later for a reading of the error codes. It was P1133. Auto Zone says O2 sensor at a cost of 0. I was in the area at the time and had surprised my wife with a lunch date.
- 2 months later I went back to a different auto Zone store about 50 miles away. Codes were P1133 and P1155. Their code system was down and they thought it was an O2 sensor.
- I spent some time on the web only to learn that some 99 Camrys have "narrow band O2 sensors" and others have "wide band O2 sensors". Now what do I have? Auto Zone only had narrowband sensors and neither store had any idea what a wide band sensor was. Just as a note, they are not interchangeable.
The real diagnosis: My very good friend Bob has a 99 Camry just like mine. I disconnected his O2 sensor after learning how to differentiate wide band vs narrow band sensors and measured the resistance on the terminals. I then compared his readings to mine. My O2 sensor readings showed an open circuit on all terminals. This proved to me that mine was defective.
That experience made me wish I had a method of doing some in depth testing to prove a $185 part was in fact defective before I bought it. Some testing software which could watch the operation of various sensors would prove very valuable as On Board Diagnostics become more intelligent.
- I ordered a wide band sensor from a local Car quest parts store. Came in a day later at which time I had to prove to them it was NOT a wide band sensor as per the notes in their system. None of the 5 sales folks had any idea what a wide band sensor was even though the sales person on the phone assured me the sensor was a wide band sensor when I ordered it.
6 Ordered a O2 sensor for a California car from car quest (seems like all California built 99 Camry cars have the wide band sensor) at a cost of $185.
- Part came in a day later, Installed it , disconnected the battery to clear the ck eng light and all is OK. Have had no ck eng light for over 2 weeks even after a 350 mile round trip.
Interesting, removing the ECM fuse for about 15 seconds did not clear the ck eng light.
Now you know why I am asking for opinions from people who have used OBD2 software. I have laptops and PDA's so connecting them is no issue. What I would like is the ability to gain a lot of information, resetting error codes, eng ck light, reprogramming the ECU if possible for some minor functions, watching the operation of the various sensors, etc etc etc.
Hope this info helps someone with their problems. The entire process took over 4 months. Luckly my car is not due for emissions testing until Feb 2006.
Dan