Update:
So I checked the crank position sensor today.
I set the multimeter to 20k and didn't get a reading.
I then set it to 200k and got 12k which gave a slow exponential decline to 6k at which I stopped.
I set the multimeter back to 20k and got a stable reading of 4.4k Ohms.
According to the testing parameters of the sensor as shown in the picture, the range of resistance is between 1,630 - 2,740 Ohms.
I took another reading and the multimeter stayed at 1 on all resistance settings every single time I tried, indicating an open circuit.
Hence, I believe the crank position sensor is the issue here. I have no idea why because I haven't actually touched it or removed it. I did disconnect the connector to replace the water pump, but that's it. Also, as stated before, the battery was not disconnected.
So I guess this is my problem? I'll look for a part number and order a new one from Toyota/Lexus.
I also check the cam position sensor, and got a reading of 740 Ohms, which is slightly below spec, but I don't think is causing the issue?
Just to be sure, I'm going to remove the valve covers again and reset the vvti cam gear and redo the timing for a third time.
Thanks!