I have a 2007 Honda Civic LX 4-Door Sedan.

I was driving and my cars engine all of a sudden just died. The Battery icon came on and the engine just died in the middle of a turn.
All the electrical were turned on just the engine died.

i was able to stop the car, put it in park, turn on the car and continue. About 20 minutes later it did the same thing in the middle of a drive.

Here are a few things that i think might be causing the issue. The passenger side does NOT have the inner fender wheel cover. So when i drive, water from the wheel probably splashes in the engine bay and all its components.
I did hear my alternator or timing belt squeeking every now and then. Not so much i would say.
Today in particular, there was a severe thunderstorm and it poured badly. I was running into puddles etc. However, i didnt notice any rough idle immediately during or right after entering those big puddles. The rough idle would happen in the middle of driving smoothly (which was weird)

My guess is that water somehow is splashing all over in there and causing mayhem.

The other thing. I changed my battery recently. I did the job myself. When i went to check the battery, i noticed the terminal connections were stiff and did not budge. I assumed i clamped the terminals down properly.
However, the clamp that holds the whole battery down was pretty loose.

When the battery died on me in the middle of driving the first two times, i didnt get any check engine lights.

However, when i went home, i let the car rest for 3 hours.

I went back to the car, turned on the engine and let it run idle. It stayed stable at 1rpm.

However, i gave it some gas and i felt a tiny stutter as the RPM went up and then it roughed Idle between 0.5 rpm and 1.5 rpm for around 3 - 5 seconds when the needle went back down. It didnt stay at 1 RPM like it usually does.
after doing that for a while, i connected my Autel MK808S to scan for the code and i got P0171 - Fuel system too lean (both permanent DTC & Temporary DTC).

I also got 61-1 Permanent DTC - Modulator-Control Unit initial IG low voltage.

Im not sure what steps to take from here. I checked the LIVE DATA while having the engine running and leaving it idle. Alternator was at 50%, battery was at 14v.
Maybe i need to check at particular intervals? Maybe i need to check fuel injector data? Maybe something is clogged? EGR? Vaccum Leak? Spark Plugs? Ignition Coils and Wires?

This graph shows Battery and Alternator while idle.

Any help on next steps would be great. Not sure