With myself being a toyota mechanic I would go with a new toyota injector. Although they are really expensive, you cant go wrong with this option. Reman injectors are a total gamble. Ive seen several threads on here where the owner put reman injectors in and one was d.o.a. and the other didnt...
I have run into similar situations happen on these 4runners that im working on at my dealer. They have been the rear door ecu and sometimes the harness connector that plugs into the rear door ecu gets corroded. im assuming this could be whats wrong with yours but who knows. There is also a tsb...
I would check fuel trims if you have a way to get that data. Im guessing an injector or two are running lean. Could also be the evap system purge valve. I have seen those cause a lean code too.
If your brake light fuse is blown it wont let you shift out of park. You will have to push the shift lock button on the shifter. I would also make sure you have working brake lights at this point
Ill put my money on a mouse chewing the harness on bank 1/Passenger side f the motor. Start looking for chewed wires or mouse nests. let us know what you find. I see way too much rodent damage to wires at work and this sounds like its a good chance that thats what it is.
Was the replacement park/neutral switch OEM or aftermarket? This seems like voltage is being carried over to different circuits via corrosion or shorting somehow.
Ok. sometimes thats all it takes to set the check engine light. We had a tacoma at my work with a similar problem where the front O2 sensor would drop its reading for 3 seconds and this caused no throttle response whatsoever. Except in this case it took a long time to find becuase it wouldnt set...
Your next step would be to swap the injectors. Swap #3 with #1 and swap #6 with #4. I have to do this every once and a while at my work (toyota dealership) and this would help me narrow it down. Injectors can ohm out ok but this sound like a flow issue.
C1201 is engine control malfunction right? If it is this is normal on vehicles with VSC when the check engine light is on. Basically its just saying that the two arent working together until the problem is fixed.