Misfire code P0302

Steve w. Filter was changed about a month ago. I will be replacing plugs with motorcraft plugs, I will test fuel pressure this weekend.

I replaced mass air sensor cleaned with the cleaner and replaced the harness, I know isn't good but went to wrecker yard when I installed the mass air flow it for rid of my p113 code and cleared the rough idle, this weekend I put in sea foam in tank, replaced the 2 spark plugs to that cylinder then had a notion of tapping injector. Cleared the code drove truck around for maybe 1/2 hour no code I then stopped at a stop sign went to shift go check engine light started to flash then became solid with that code again. It seems that the code doesn't flash as fast as it used to used to go maybe 6 minutes till it started to do it this was the longest it went before flashing.

Oh and yes I did look at the plugs they look almost the same as the new one, no carbon, no moisture, no oily residue and this being 2 plugs per cylinder im not sure which side it is causing the problem. Also hopefully someone will know does this have a crank shaft sensor and where it is at? I can't locate it at all

So today I rechecked all connections, all were good reset the check engine light took truck for drive put gas in to it took it on freeway at 65 let up drop to 40 then jumped back on it at 65 no check engine light. Went up and down different streets different speeds etc. Nothing till I got near my place and it kicked back on. Thought well maybe idle it too high adjusted that and a gain drove around for quite awhile it came back on again, so then I reset the check engine but this time I swapped the relays around and no even 20 feet down the road check came back on. So question is the fuel relay possibly causing this misfire on cylinder 2?

Should say I drove it about 40 mins with no check engine light on

Now I did buy a stethoscope and the injector was opening and closing sounded good, now is it possible that the o2 sensor is going out or carry converter clogging up

Ok so i'll need to remove the injector is it best to remove the the riser to the throttle body or can work it out easily

Ok seeing how I have problems with the number 2 cylinder I went and bought a injector and replaced it, I started the truck it bubbled and farted then died, not it won't start at all it'll fire but cut it's self off. Am I supposed to purge the line? I started by loosening the gas cap removed the relays, disconnected the battery and pushed the fuel valve
took off throttle body, then started removing bolts to intake to upper half off after many cuss words at on bolt that wasn't coming loose I decided to loosen the bolts on the fuel rail I had enough room to pull the # 2 injector out, replaced the injector, and re seated them, re tightened down all the bolts and replaced the throttle body, replaced the pcv valve seeing how I broke the other one.

I checked the firing order all is correct did not remove or even move riser last bolt was securely tight, so hopefully on sat I can check the valve, maybe just need to crank on it a few times to build up pressure? And i'll recheck throttle plate gasket so I can make sure the vacuum line coming off throttle is secure in there

I should note that originally when I started taking things apart I removed the relays and opened up cap to the tank also noticed when I depressed the valve there was fuel coming out relieving the pressure, is it possible the kill switch was tripped or a bad relay?