You seem to know what I wish I knew. Pardon me for horning in on this thread.
So the sensors are easy enough to remove and insert to just swap them, instead of putting in new? Because they cost so much, about $125 (for Toyotas, a lot more for BMWs I supppose.) (Of course I have the same code on both banks so I guess I won't be swapping, but taking one out worried me.)
I have a P0171 (Bank 1 too lean) and the same thing for Bank 2 (P017?) They tend to point to bad oxygen sensors
2005 Solara Camry Conv. with 3.3L
I've looked repeatedly and diligently for vacuum leaks. I've sprayed starter fluid into every crack. I've checked every hose.
I've cleaned using the special cleaner and then replaced the "filter" in the air cleaner tube. I've checked the air cleaner and it's clean.
I think I once made the codes disappear for 2 or 3 hours** apparently after I sprayed Liquid Wrench on the upper 02 sensor behind the radiator, when I was planning to change the sensor, but I couldn't reproduce that by spraying again. Still, it makes me think there is a leak there, in the threads?, that won't be fixed by merely replacing the sensor.
**Usually the codes reappear 15 minutes after being cleared manually.
I don't know how to check injectors, but since it's both sides and the car runs evenly, maybe they aren't the problem?
The two symptoms are two lights** on the dashboard and the fact that it usually stumbles, hesitates, when starting from a dead start, unless I press the acc just right. **VSC and what I read followed from VSC, trac off.
From reading I did months ago, I'm thinking the upper 02 sensors are more likely the problem than the lower ones, and I should replace the one that is easy to reach.
Or I could diagnose it the way you suggest, but the scan tool I bought didn't work completely and I returned it. I could buy another.
So I could be ruining my cat converter?
I'm hoping it's not that bad because I get 31 mpg on the highway, 1 or 2 mpg higher than what Toyota claims for the highway for a 2005 Solara convertible with 3.3L engine.
It's quite a bit lower in the city and I'm figuring I waste a bunch of gas every time I leave a stop sign and it stumbles.