A/F Control test

As an example or as a suggestion as to where I look for my problem?

 

I'm going to run the "status monitor tests, but I'm confused about two things:
1) The CAT test says to go into Inspection Mode (IM) and drive for 20 minutes. All the other tests warn about driving in IM - is this an oversight or safe for periods of time?
2) The other tests instruct to connect to the Smart Tester, Enter IM, then exit IM without turning the power off before driving. How do you manage that (since turning the power off is the way to get out of IM)?

 

I verified the O2 Heater is drawing current (about .76a), so that doesn't explain anything. All my "monitor tests" have passed, although i'm still confused about how to exit Inspection Mode without losing my OBD connection.

In any case, I'm stymied, unless someone can suggest something to try. I guess I'll let Toyota diagnosis it..

 

Sorry, I changed my sig when I bought the new Prius. I'm trying to sell my 2005 Prius (with 215K miles), and a check engine light is a severe handicap to selling.

 

Wish it hadn't shrunk so much...otherwise, I love it.

 

Although it was a little effort to replace the A/F Sensor, this was apparently the problem. Even after removing the inverter, the access is still tight, and your typical sensor wrench will require milling to fit the heat shield. I think replacing the O2 sensor would be an obvious first choice, but as others have discovered, the code points at the wrong sensor. The wikipedia entry about A/F Sensors mentions that they do go lean when they age, which would make the ECU push the mixture in the rich direction.