2.3L ('83-'97) 2.3 intermittent misfire only at operating temp

[Zapper]

So i just recently got my ranger running once again and ive been driving it a bit to see what i have to fix next and it has been misfiring when the engine is ar operating temp, ive replaced the coil, distributor, distributor cap, plugs, plug wires, timing belt, and headgasket in the past 3 months. Im unsure how to describe it so i just recorded it instead

 

[Dirtman]

I hear a horrifying exhaust leak...

 

[Zapper]

I hear a horrifying exhaust leak...

There is no exhaust actually, I have to figure out how im going to put a muffler on it that makes it quieter but is still hidden underneath the cab.

 

[Dirtman]

Well that'd be your problem, or at least it's not helping and making the real problem unidentifiable. Is it carb or EFI?

 

[Zapper]

Well that'd be your problem, or at least it's not helping and making the real problem unidentifiable. Is it carb or EFI?

EFI, and its been open header for quite awhile and its never had problems like this before

 

[Dirtman]

Where is your o2 sensor located?

 

[alwaysFlOoReD]

I'm with dirtman. With the o2 sensor exposed to outside air the computer will screw up air/fuel ratios. Perhaps there is a crack or loose fitting coupler that is letting in fresh air above or close to the o2.

 

[Zapper]

Where is your o2 sensor located?

Its located at the end of the exhaust manifold, and it has about 1ft of exhaust piping after it