1999 3.4L Warm Start issue and code P0171

I have 1999 Tacoma 3.4l. The truck has intermittent warm start issues. Occasionally after the truck has warmed up if you park for 5-10 minutes it will have a hard time starting. The engine will crank and you hear it trying to start but it just wont "catch" for lack of a better word. Usually within a minute or two of attempting to start it will fire and run fine.

The other day I was driving and I got on it a decent amount and I later noticed the check engine light was on. I checked it with a code tester and it came back as error code P0171: System too Lean (Bank 1)

So far the following has been done

Replaced IAC Valve
Replaced MAF Sensor
Replaced ECT Sensor
Replaced Fuel Pump
Replaced Fuel Filter
Cleaned and Balanced Injectors
Replaced TPS
Cleaned Throttlebody
New Plugs
New Air Filter (non-oiled air filter)
Checked Valve Clearance

Any ideas?

 

Oh and both O2 sensors were already replaced.