my wifes 2005 f150 with the 5.4L in it started running rich and stalling out. it gave me a code for injector in cylinder 8 so i changed it out and cleared out any gas that might have been in the combustion chamber. Started it back up and still running really rich and stalling out. Also almost forgot to mention i changed the spark plugs and coil packs out about 4 months ago with ford parts. so i am currently at a loss on what might be causing this issue. Any help would be great.

 

Not good changing injectors one at a time . You should at least changed 4 on that side. Injectors are controlled by the bank not by each. Plus how are you going to keep track of old vs new .
You need to look at torque pro , see what your front o2 are doing . Plus clean the throttle body and maf . I just replaced all injectors they were changed once but had 125k miles on them . Number 2 was wider open steam ,no 5 was dripping .
Lay your fuel rails out on newspaper turn key on for fuel pump none should drip .

 

ok will pull them all out and turn on pump to see if any leak

 

Apparently you haven't heard of sequential fuel injection which is what Ford uses. Every injector is controlled by pulse modulation of the ground circuit. Injector (timing) IS a thing. Replacing more than one injector without testing is what we call firing the parts cannon.

 

After fords extended warranty on 2005 bad injectors which they would only replace a bad injector. I went ahead at 130k and changed them out . You may be right about injector timing , I know each one has a ground driver . What I was referring to was was millisec pulse width that is decided by pcm using one o2 sensor on each bank . Between the o2 and maf it sets the ms pulse to correct fuel mix per side.
It doesn't help when you mix different injectors on a bank . My latest injectors are 4 hole from duralast ,the ones I removed were 2 hole . Injectors can destroy your engine hydro locking your cly. My number 2 was flooding in a solid stream without a signal on it , number 5 was dripping . Number 2 thankfully flooded intake manifold removing the black build up from crank case vent, it then caused all that black oil to burn thru bank one cat . It smoked heavy for 2 solid miles . It now goes thru intermittent code for failing bank one cat .
So you see the age and miles on injectors due to heavy use is an indicator of failure rate of all of them . My engine is at 258k and did not hydro lock or I would be looking at a 8-9 thousand dollar engine . I stand by replacing all injectors at a time when they get to this point . Anything over 100k miles or failing /dripping is a good case to change them .
I first saw hard starting then i watched fuel pressure , I noted it would sometimes not hold pressure very long after shutdown so I guessed the fuel pump check valve was leaking sometimes . I felt the injectors must be okay since I had changed them all so the fuel assembly was orig so I chose to replace fuel pump . Big mistake , I no longer have faith in injectors .