Old Member ... New Problem

I've been a member since 2006, and this is my first real Prius problem. I hope I can get some help.

I have a 2006 Gen 2 Prius with 123k miles. About 5-6 weeks ago I got the red triangle after the car sat all day and I just started it up, I have something like a scangauge (built by someone on here long ago for the Prius) and I can see and clear DTCs. I had P0000 , P0130, and P2400. I believe: P0000 is pretty non-specific, P0130 is related to heated O2 sensor 1, and P2400 is something in the EVAPsystem.

Since I was far, far from home I cleared the DTCs, and the car drove okay. I did notice the traction battery didn't hold a charge well as I drove and the SOC (number of bars) went down dramatically when used. I could sit still maybe one or two minutes before it would fall from the highest blue bar to the purple bars. I made it home with only a hit to the MPG.

I decided to try condition my traction battery using Prolong's system. I hoped that I could recover lost capacity. Conditioning/cycling took a few days, and for a host of reasons, I let the car sit for four weeks. I have a 5-year old e-LearnAid yellow top 12V conversion, and I put a Battery Tender on it so it's okay. A few days ago I put the Prolong trickle charger on the traction battery and charged it to 238V in about a day.

Well, I got the car going earlier today with no problems. However, the traction battery was back down to only one or two bars (I had just fully charged it a few days prior). I got about 5 miles down the road and suffered a repeat of the red triangle and the same 3 DTCs I'd experienced weeks ago. The traction battery was acting just as before, and it wouldn't hold a charge.

I stopped and cleared the DTCs, but today the traction battery didn't come back. It was stuck on one bar and wouldn't take a charge (zero amps were going to/from it). I limped home with a max speed of about 40 mph. Surprisingly, the red triangle didn't come back. Likewise, no DTCs.

So, any ideas besides changing the traction battery? Any ideas if the DTCs are anomalies due to the low traction battery? Are P0130 and P2400 in any way related?

Thanks in advance.