SEL V6, has engine stutter, engine codes read misfire on 4,5,6 cyl, with code p0171, bank 1 running lean, will changing fuel injectors fix this? or is it more in depth?

The fuel injectors seem to be very misunderstood, because
everyone seems to want to change them
They seldom ever fail & if someone goes that route
in diagnosing a ford misfire, there wasting their time.
Check them yes,if it makes you feel good

You change absolutely nothing on any vehicle
until it fails

You change nothing until you understand how
something works & how to TEST it

On a Ford or Lincoln you disregard all the misfire codes,
when you get more than one at once

The 171 O2 Sensors Code is from the misfire & resulting
lean condition

What you have is 1,only 1, Bad COP Ignition Coil

You buy one for $60.00 & put it in one of the PO300
Code cylinders & drive a few hours in hot weather
If the problem is still there (forget the codes) you put
back the old coil & move the new one

If you have all kinds of fancy oscilloscope & inductive
coil probes etc you can do all sorts of neat things

Look at primary side of coil ,secondary side of coil,
current ramp your fav the injectors etc

Easy job --buy one coil & put in 4,5,or 6

1,2,3

4,5,6

front to back

I suspect 1,2,3 will be next to the firewall
if a transverse engine

Clean MAF Sensor ----CRC MAF Cleaner

Change front O2 Sensors at 100,000 miles
Napa Auto Parts has OEM Bosch or NGK

You can verify injectors by, ...running at idle, unplug one at a time, if the engine rpm's goes down, that injector is working. If no change, you have an issue at that cylinder, being spark, fuel or compression.
I do know that some of the fords with plastic intakes are know to have intake gaskets (plenum) that harden and leak are. I would look into that.