aw geez, whats happening to my flawlessly running prii? Triangle, DTC issues

I bought a gen 2 with 109k in April. So far, I am loving it. Road tripping, going from the Atlantic to the Pacific and back, I have put 11,000 miles on it since spring. Recently, I have been running into issues. Having owned and maintained a high mileage chevy astro van, I'm no stranger to hard work and researching car problems. Anyone who has owned a gm van will tell you, there are many issues. Ok, here's what's going on with my prius:
I've noticed a 10 MPG drop on the display and over the last two days, I keep getting the triangle and other warning lights along with loss of power. Usually happens after a mile of driving but today it happened when I started the car. I have used a Bluetooth OBD2 reader I have gotten P010A and P0111. Today after clearing, I get P0130 also. I learned from this forum that P0111 and P010A are not actual DTC's for gen2 and I need to get a different wire/techstream(ordered).
So I use an app to scan and reset the codes, triangle and lights goes away, and I proceed hoping it makes it home under sometimes reduced power. I also learned from this forum that a dying battery can cause wacky issues.

Here's my multimeter battery measurements:
12.8V after sitting for hours,
12.7V IG-ON (one push, no pedal)
12.5V ACC (two push, no pedal)
when I go to push the pedal and start it from here, the voltage drops to 12.3, then goes up to 13.8V when the car starts. When I read the voltage using the cars menu on the display (in ACC, hold info button and flick lights 3x), all the voltage values are about .3V less on each.

Do you guys think its the battery causing problems?
Can I trust that P0130 is an accurate DTC's for prius?
Is there any paid app that will load the correct PID's to accurately scan or do I need need techstream to find out for sure?

Thanks you guys! I love this forum, the search bar has been invaluable and the advice has been top notch.
This forum's got something special going on

 

I have Torque Pro, Dash command, Dr Prius, and Scan and Go.
The free Scan and Go seems to be the fastest and most reliable at connecting and clearing codes.
I bought a battery from Toyota yesterday, but after doing more reading about my voltage, I'm hesitant to put it in

 

Torque pro, hasn't been connecting properly but reads 0 fault codes with repeated attempts. I can't get that app to function correctly.
That's a great link, thank ya!
Also, thanks for verifying my battery specs. I was a little unsure, but I really appreciate ya letting me know.

I took the MAF sensor off and cleaned it with MAF cleaner.
I took the air cleaner off and cleaned the Throttle body. Blue shop towel doused in TB cleaner wrapped around a screw driver worked pretty well. Maybe the shop towels from walmart aren't as strong as others or something because I would stick one sheet wrapped down there, gentle wiggle it but the blue towel would flake/chunk off so easily. I had to wet the end of screwdriver to yank out 3 large chunks of towel out of the throttle body. Surely that could cause a problem, no? I blew air into the TB and was confident I got the towel pieces out. Closed it up and went for a drive.
New codes I've got P0201, Injector Circuit Malfunction - Cyl 1 maybe from the loose crud that got moved around, I'm not sure. The code hasn't shown back up so I think I'm good.
All the lights and same codes are showing up. I get my techstream wire hopefully tomorrow

 

Thanks SFO, I've had the PID's loaded on Torque but once connected and scanning for fault codes, will stop around 30% and say no codes found. Dr. Prius won't connect anymore and neither will Dash Command. I'm using a Google Pixel 2. I have only been scanning/clearing with the Scan and Go app
I pulled out my old Galaxy S5 and attempted connecting. Dash Command was the only one that would connect and when I went to read codes, said none found.
I've tried with the car on, ig-on, and acc mode.

One thing I've been noticing is fan noise coming from the cool air intake on the rear passenger side wall. I don't remember it being that loud.
The car has been sitting all day. Is that fan supposed to come on with two pushes of the power button into IG-ON mode?

 

Dang, I was hoping it wasn't the hv battery. I haven't inspected it's fan yet, but I will check it out.
My OBD2 is old that it's probably not operating right. I popped it open and found it to be one of those single layer ones.
I should have the techstream wire tomorrow and will know more.

Thanks for all your help, you guys are amazing

 

Sorry for the delay, I've had to attend to family matter.

I'm looking at this MiniVCI wire, J2534 V8.10.021. I thought I had ordered a version 13 but I must have made a mistake. Is V8 sufficient to read all the codes in my gen 2?