Occasionally dies at idle

2000 Tacoma 3.4L v6 I’m struggling to diagnose the problem. It seems like 99% of the time I’m running great. But occasionally I’ll repeatedly die when idling/going under 20 mph I hit a deer recently and had quite a bit of work done, replaced ac condenser, radiator, clutch fan. I have been throwing p0171 engine too lean ever since I acquired the vehicle, I found a vacuum leak and that did not fix the problem, after dear hit it was driving like shit and I found out the cat had cracked and separated from the engine I thought “great! That thing was probably already cracked and causing a vacuum leak and the. It fully separated and is causing the issues” I replaced it and the code went away for many days but then came back.
The dying at idle seems to be exacerbated with lower octane fuel batter is very healthy.
All spark plugs were replaced a few months ago, brand new air filter, cleaned maf….
Yesterday when I was experiencing issues I also threw code p0340 for the first time

can anyone help me with what data I can gather to attempt to diagnose what is going on?

 

Did it have this issue befor the deer strike?

This is going to be dificult as the things you want/need to monitor are not monitored via the scan port. The first thing I would do is locate the ground wires on the intake manifold by Toyotas scan port and wiggle them one by one, then tug on them a little, one by one while it is running.

Tacomas use what is called a circuit opening relay for fuel pump operation. There is no fuel pump prime like in other vehicles. When you crank the motor over the signal from the starter closes the relay and after you release the key the signal from the crankshaft position sensor keeps the relay closed. Having said that you can wire in a #194 side marker bulb into the blue wire that is under the D/S carpet and position it where you can see it. The blue wire is the wire for the fuel pump. If the light goes out while driving something is opening the relay. There is the possibiltiy that when the motor stalls the relay opens and you could be chasing your tail, it all depends on when the light goes out, light goes out and the truck stalls, you are onto something, as long as the motor is turning over and above a certain RPM the light should stay on. I hope this makes sense.

All I am trying to do is to eliminate one thing at a time... is it electric-fuel related, electric-spark related etc.