Hi, I'm Dan. Looks like you have a P0316, which is a code for misfire at start up, meaning when the engine is cold. Also the P0304 points to cylinder #4. Those older 4.0 Ford engines have a tendency to have issues with the intake manifold rubber gaskets. (See attached picture). As the engine ages, the gaskets shrink and leak when cold, but swell up just enough when warmed up. Try to see if you can hear a whistling at t first start up. The next step would be to have a shop smoke test the intake manifold to look for leaks.
Another approach may be to just change the gaskets as the repair is pretty straight forward and can be done in an afternoon easily. Also, the parts are inexpensive.
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Friday, October 29th, 2021 AT 1:48 PM