2013 prius v with stalling sensation

Hello all. I have a problem that I can't seem to find an answer for. Sorry this is a little long, but i want to make it as detailed as possible.

My prius v in the last month had started to act like it was stalling on me when it would change over from the electric to gas while accelerating from a stop. It kinda stalled out once when I was coming out of a driveway. So it sputtered and jerked but didn't cut out, almost like a manual transmission when you aren't coordinating the gas and clutch right. At that point I turned it off and back on and it was fine. All of these times I had the ac on and fan was on high. When I turn the ac off the car accelerates fine. And it is only when the battery would be down and it kicks the gas engine on.
I took it to the dealer and they said it needs spark plugs, all fluids switched out and the throttle body cleaned.
I changed the spark plugs and it was running great again like it should. That was 4 days ago. Today it is rainy and hot, so I had the ac on all day, and then I turned the defrost on and the fan was on full blast. I came to a stop, that's when I turned the defrost on, and when I went to pull off the car started to go then stopped. Still on, but not accelerating. I put my foot on the brake and try to pull off again, same thing happened. Almost feels like a belt slippage, but from what I read there are no belts. At this point I am in the middle of an intersection and have to move, so I turn the defrost and fan completely off. The battery is down and the engine kicks on and then I am able to take off at that point. It was fine the rest of the way home with the fan on low.
Any ideas to what this might be?
Oh and I bought it about 2 years ago with 135000. It now has 203000
Thanks for any help!

 

I drive my car for work. So the ac was on when it was like 95 out. But then it started raining and the windows got fogged up so I had to turn some warm air on the windows.
I did have to add some antifreeze like two weeks ago but it has been fine since. The inverter coolant is fine.
When it was cold a few months ago I was getting a loud rattle when starting. Since, it has just been a very light rattle that lasted a couple of seconds. After I changed the spark plugs it was smooth when starting.
Will pay a bit more attention when starting tomorrow.
I drive like at least 100 miles a day for work with constant stop and go and the engine doesn't really get a break for a good 6 hours or so.
Will try to clean the throttle body and egr valve as soon as I get a clear day without rain.

 

Pensacola, Florida

 

Ok. So I have started the car twice now, and it sounds smooth.

Driving a few hours later it started raining. I turned the fan on medium and for the past hour every time I pull from a stop it hesitates and I have to slam the gas to make it go.
Will try turning the car off and on now to see what happens

 

I follow the maintenance as far as I know! I take it to the dealer every 10000 miles and get everything they recommend. But this is my first prius.

No dash lights at all.

Have not cleaned the egr or intake manifold yet. While driving today with my husband he Said he thought it might be the mass air flow system since it only does it when it is raining ever since the spark plugs were changed. And the dealer did say that the throttle body needed cleaned.

Will check the fluid tomorrow.
Thank you for all the questions and suggestions. I sure hope it's not the head gasket! Really can't afford to fix that at this point in time.

 

I looked up what a rough idle sounds like. If this is what you all are talking about, my prius never made that noise!! Thankfully.
https://youtube.com/clip/UgkxgC8dzTqjdAs1i-JHeY9diEayzouHcIjh

 

The coolant loss was a couple weeks ago and it hasn't went down since then.
I did check the inverter fluid for movement and it was moving. If I'm correct, that is a good thing though, that means the pump is working.

But will update after the maf, throttle and egr get cleaned.

 

Tim Well, I never actually looked to see how much coolant was in the car when I bought it. But what made me check was that the temp light popped on when I was on the expressway. But it flashed on for like 2 seconds and went out But never came back on. It was like 120° and I was doing like 90!! So I checked, saw it was at the low line and put some more in there. That was almost 1 month ago and the level has not changed!

 

So we cleaned the throttle, maf, and the egr today.
To say the least, everything was very gunked up and filthy. Took for a test drive, heard the computer making adjustments, and it runs way better than it has in a while!! Will update in a week or two after more driving!

 

Well it was more so of the engine high revving for 2 seconds, then low revving for a second, then leveled out!! But from a video I watched, it explained it as the computer making the adjustment from it being so gunned up and open wider than it was supposed to be.

 

Well, a small update. The car was running fine, until I went to work delivering packages. Stop and go with the ac on and once the hv battery got down to like 3 or 4 bars and I went to pull off from a stop, it did the crazy stalling thing again!!
I am starting to wonder if it might be the battery.
I turned the ac off and was able to drive and do the deliveries no problem.
I have an obd Bluetooth thing coming this week so I can hopefully test the battery with the Dr prius app.