Martijn van Duijn wrote:

> Would you guess on of the above are more likely than the sensor itself
> being bad?
> Easy enough to swap 1 and 2 and try, judging from the other posts.
> Platinum plugs and wires are 20.000 miles old, I'd be a bit surprised if
> they were bad. Wouldn't vacuum leaks affect both banks equally?
> Injector? Perhaps... The engine seems to run OK though. I can try a
> cleaner at some point.

The highly active bank 2 sensor would typically indicate a poor
catalyst on that bank, or an exaust that hasn't reached temperature yet
(not likely since the other side is OK). The bank 1 sensor on that
side shows a less than ideal trace, so you could simply be overloading
that catalyst with excess fuel or air. Since you are using your OBD
data stream to create a graph, your result is a low resolution and
inaccurate (in terms of real time) chart. Note the random pattern of
plot points compared to B1S1.

Anyway, look for something that would cause a mixture issue with one
bank, like pluged EGR ports in the intake, leaking vacuum hose(s)
exiting from a specific runner of the intake, bad injector, wire, etc.
Do you have any cylinder misfire codes? Can your scanner read live
misfire data engine running?

Toyota MDT in MO