Misfire #3 p0303

Can anyone please help. I have a 1997 Tacoma 2.7 5speed 4x4 300,000 miles . I have never had any major problems i was trying home about 30 miles and then I stoped at Walmart and when I started to leave i had a miss fire and this is what i have come up with so far I have a Misfire #3 p0303 and we have done a compression test injector on number three ,both coil packs spark plugs , plug wires,. smoke test ,check compression,cat seems to be good. I have took it off and straight piped it to just check.ive checked oxygen sensor’s .i can clear code and i dont show misfire code when idling but I can feel its still. Put in gear and start to go it will pop up soon as I start going. Ltft is 19.0 I have noticed that sometimes it will stay in open loop and finally go to closed loop after a little bit but when I put on the gas it will say open loop fault some times and sometimes it will say open loop drive and sometimes it may say closed loop. I can’t figure out what’s going on. Coil is pulsing and firing strong. I took spark plugs out and it looks like #3 is a little darker. And I’ve changed spark plug with 3 different brands just to be sure it wasn’t the plug. If anyone can please help I would appreciate it.

 

What was the results on compression test? Did you put new injector in or just test them? If you have all new spark plugs, coils, and wires probably the injector, your plug is loose or you might have something leaking into the cylinder or wires arking. faulty new parts is a possibility. You loosing coolant?

 

148 147 148 148 changed the injector and then put another new injector because I thought it was faulty but same results. No coolant leak and did straw test on cylinder and nothing was in there. And I just put new spark plugs in again today and it’s running a little bit better but still missing the spark plugs I took out was ngk and I just put champions in today. When I give it gas driving it my scan tool is saying open loop fault for fuel and I let off and it will go back to closed loop

 

I just checked my injection pulse and didn’t have pulse on #3 . So im guessing its a bad ecm.it’s grounded and wires look good