Reset your ECU and see what codes you pull up. I don't know how to do this on a Toyota but i'm sure someone will post really fast on how to do it. Usually involves unplugging the battery for 20-30 minutes and then plugging it in and letting the car idle for a long time. Or maybe you are supposed to drive the
out of it. I don't exactly know...
I do know. if you just plugged in a sensor that has been disconnected, then your ECU has mapped your A/F with a bad setting, and need to be remapped, IE Reset your ECU.