P0171

I have tried the cleaning of MAF sensor so far.

The code pops up every time I do a curve (during acceleration), or I gas in a slight elevation.
If I gas easy or pushing acceleration the code does not come out, even at high speeds.
No mpg difference that I have noticed.

I have ob2 reader, and an app that gives the option in the video below. Not sure which readings would be something to look at to help diagnose.

I try getting diagnosed at Toyota once, they told me was the 12v battery, but I had that put up just 3 months ago, and had warranty on it. Showed Toyota findings and got a new battery on. Purchase a battery charger to charge this battery full.
Charged full to 13.7, and idle after 24 hours on staying at 12.5, but with all lights on, and no 0 ready on, it stays at just 12v, not sure if this is acceptable for a new battery.
With everything on is high on the 14v range.

I just hope is not a fuel pump, have being putting lots of time fixing some other things. Got both battery in, fixed the odometer meter screen, and got a new inverter pump installed, all of which satisfied all the other codes I had, but this one is just too many possibilities.
A question I have also, is if you guys feel is Ok to try a injector cleaner, in case such could be a problem, and if there is any chance to solve the issue in case it is due to injectors.

Doing a few drives around I can see oxygen readings and the MAF readings, so I know they at least not dead, but know they still could be at fault.

 

I got the ob2 reader recommended by doctor Prius, but got this app as well because it gives more in debt information.
I'm actually thinking it could be the O2 sensor now, after watching some videos, because the voltage on the 02 at times gets very low. But I try checking them last night, and even though I noticed this the code never showed up on the travel I did last night.

The app in the video is simple called carscanner.
Drprius finds the exactly same code.

On the carscanner app I can plug in my exact car model and such, and it only scans for things the app is comparable with my car.
That is a very large list of things this app scan for, but many are things newer cars have.

 

I also saw that the MAF readings should pair throttle readings well, and they match quite close when I run the car and compare the two side by side.

Oh, I forgot to mention: this is for a Prius 2004.
Miles read 175k, but keep in mind I had the dashboard out for some time, so the milage would be a bit higher.
When I changed the pump, I also noticed that it wasn't the original one, so Toyota likely exchange on the recall, with previews owner.
I have the car for about 5 years now. Only now started getting problems, which started after I visit the scorching Texas.
I'm in Colorado now.

 

I did took the MAF sensor, and used the MAF sensor cleaner and let it dry for about 12 hours before I put back in.
Took for a drive, and right away the code came back on the drive off.
The sensor look pretty clean as I took it out, but I spray it good anyways, letting drip in a vertical way as I seen some videos suggesting.

Edit: also I try that over a month ago already, and code persists

 

Took everything apart, clean again sensor, cleaned throttle completely. Throttle was pretty dirty.
My gas mileage went down, acceleration got much better. Ran for a while yesterday, no codes.

Today around the mall area, taking a curve, code came back again on engine light, so, at least cleaning can't be a problem.
The MAF actually look good. But did a cleaning all around again just in case.

 

Thanks for letting me know the types of scan data I should look for.
I'll do some test drives with those readings running on the background and post as soon as I get them.

I did one before cleaning the throttle running the throttle and MAF sensor on the background
I notice the code came out just as it hit 36% on the throttle reading.

I didn't get the time to do a drive with readings on the background after cleaning, but I'll try to do so ASAP, and test the other things you mentioned as well.
Only problem with app that I have is that I can only test 2 things at the time, unless I purchase the app.

 

The test before cleaning the throttle a and MAF sensor.

 

Test done driving the car and stopping once check engine pop up.

The test below was done after I let the gas tank run close to empty, put engine cleaner on tank, filled up with the highest octane available on a chevron gas station, and use the tank to about half before performing test.

When I left the gas station with full tank the check engine light came out just as I left the gas station on the turn to the road.
The highest mph I have seen the code was around 42mph.
Usually happens in the high 30s, but my last test, which was the fuel trim high/low, the code popped up going only at 17mph.

After I post this I'll try to upload screenshots.

 

Screenshot_20210611-150851 by Cometflash posted Jun 11, 2021 at 2:53 PM

Screenshot_20210611-151218 by Cometflash posted Jun 11, 2021 at 2:53 PM

Screenshot_20210611-151338 by Cometflash posted Jun 11, 2021 at 2:53 PM

Screenshot_20210611-151622 by Cometflash posted Jun 11, 2021 at 2:53 PM

 

I could buy the pro version.
The pro version of the one I have is 3 dollars, torque looks to be about 5 dollars, but if you know torque, have used and recommend it, I rather get something more familiar to you.
Would buying torque pro allow me to provide the information to you?