I've got a scanner, now I need help diagnosing

No you don't need to drain the oil to do valve cover gaskets, if you are close to being due for an oil change do the gaskets and seals, run it a bit, then change it.

 

Just be aware of when you remove the spark plug the oil will drain into the cylinder and when you start it up it might smoke a little.

 

Good to know.. ill do my best to soak up the oil before I pull the plugs.

 

If you have access to an air compressor and blow gun you can spray some brake clean down the hole, stick the blow gun nozzle down, hold a rag over the top, and blow most of it out, that's how I clean them at the shop just wear safety glasses, brake clean burns if you get it in your eye

 

Cool, thanks for this.. and just to confirm with you since I know you've been following along to all this nonsense. lol
..I'm replacing the inner and outer valve cover gasket, spark plugs, and coils right? Is there anything else I should look for while I'm in there?

 

Cold beer

 

If the coil boots are replaceable your coils may be fine but for sure replace the boots.
You may want to glance at the timing chain and guides while your there, not a common failure point on Toyotas but it wouldn't hurt to give it a lookover.