2006 Prius - P0171 & P0302 while hot?

I have a 2006 Prius where I just replaced the fuel injectors last Sunday. Was really rough at first when I first tried to drive the car after I replaced the injectors, then seemed okay.

I had been getting the code P0420 prior to this. I have a new catalytic converter to replace the new one but not had a chance to get it installed.

I drove today to a medical appointment and I decided to drive to an old shop I knew to see if he could put the new cat in. Drive to the medical appointment was fine and my MPG shown actually increased a hair. Was there a couple of hours. Drove to the shop, which was a long distance (30+ miles) and talked to the guy for maybe ten minutes. He was way to busy to try to do the car although he is cheaper than anyone else. Do it for $90 to $150 but is cash only. He is a good at exhaust systems however. When I drove home, the car shuttered and got flashing engine light. Something similar happened yesterday but not exactly the same but I was only a short distance from home. It was also after I stopped. I stopped at the public library to get my A+ certificate printed out and was there for maybe 10 to 15 minutes as well.

It seems as if this is something that happens when the car has been running for a while, stops for a comparatively only a few minutes, and then start up and go. Seems to also be in warm weather. Been around 80 recently.

I understand that P0171 is often the MAF sensor, which I can clean. That is what one discussion suggested at least. Plugs are new, wires are new, and was not getting either of these codes before. I on occasion got I believe P0301 but very infrequently (Cylinder 1.)

I am half guessing here and could be all wrong so please no attacks for bad guessing.
Could the catalytic converter be clogged where when it gets hot, it creates issues?
Could it be just cleaning the MAF sensor?
Something wrong with when I put the fuel injectors in? Other than being fiddly, I don't see that but shrug.
Something else I am not thinking of at all?

 

I did the three things I could do easily

Removed the air box because I could not get the lower screw out of the MAF sensor. Going to have to use a special tool to remove it. Want to get replacement screws first.
Used CRC MAF cleaner on the inside of the sensor with the box off.
Used throttle body cleaner to clean the throttle body.
Put new hose clamps on the upper an lower areas on the air box so that they will be a tight seal. Was very gentle with the lower one and maybe not as tight as it could but want to be cautious.

Where else should I be concerned with unmetered air other than the seal of the air box?