what is your equivalence number showing? and what about total engine load? You are getting too much fuel into the system and your total trim is -20% which is a bit high.
You dont have an FPR that can leak to the manifold on your engine, your FPR is in the fuel tank and is part of the filter jug, the injectors can be dripping too much or you have something else like an oil burning issue. Your engine doesnt use an o2 sensor but rather an AFR sensor. it can be easily poisoned or damaged.
Check its working and reaction time while checking the equivalency number (aka lamba number).
If your scan tool is primitive - it may not read the toyota AFS B1S1 PID, you then will have to rely on the o2 graph which will show something like 0.54V constant.
Toyota AFS B1S1 PID shows up as a voltage in the tool, 3.3 V being stoich and anything lower being rich and above being lean. - its very very fast acting. Dont try to use a multimeter on the sensor as the voltage you see on the tool is interpreted and not live, the actual working of the AFR sensor is by the amp pull of either the AFR or AFL lines from the ECU.
