Hey, I've searched all over, found a few threads with my exact issue but the solution was never posted.

I've got a 2007 Fit A/T, 230k miles, bought the car in need of a valve adjustment. Did the valve adjustment and it ran fantastic for about 2 months. Then out of nowhere this starts happening. CEL codes are P0171 System too lean bank 1, and P0420 Catalyst System Efficiency below threshold bank 1. It started loosing power after you gave it more than about 60% throttle. Using the Torque Pro app I have screen shots showing what is happening when I loose power at the bottom of the post. When the car idles for about 10 minutes or so and everything gets good and warm, or like today when I got stuck in traffic and have to idle for extended periods of time. It will die and not start back for 30 minutes to an hour. While this crank and no start condition is present, fuel is not making it to the cylinders for whatever reason. Fuel relay is clicking, I can hear the fuel pump kick on and run, and the car will not attempt to fire at all on its own, but will start up when starting fluid is sprayed in the intake then die. May not have any influence on whats going on but I noticed that the radiator fan dosen't really spin as hard as what I remember it doing when I first got it, and only the large one is coming on when AC running or engine temp reaches 210-215F.

What I have tried:
1. Coworkers have suggested a stopped up Catalytic converter based on loss of power and CEL for P0420, no emissions testing where I live, so I took off the cat and gutted it and replaced upstream O2 sensor with no change.

2. Suspected possible vacuum leak based on P0171 CEL, did the spraying brake cleaner trick around running engine listening for it to idle up, no luck there.

Sounds like faulty main relays give issues after they get hot, maybe that would cause fuel to cut out?

I've drove it for a while like this hoping whatever was causing the issue would finally quit completely so I would know what to replace but it hasn't. Any suggestions? Don't wanna go replacing some super expensive parts without some guidance first. I'm scratching my head here, what do you think?