I have a 2002 mountaineer it fills like it has a misfire but no code come up

Low compression can come from 3 places. Intake valve, exhaust valve or rings. Squirt some 30 weight oil in the spark plug hole and retest the compression. If it goes up the rings are worn. If not then a valve is leaking.

fuel pump is possible. Have you fixed this yet?

Flashing MIL Lamp on a Ford, is a Class A exhaust
converter damaging Cylinder Misfire

Get your codes ,google them & diagnose the problem
& don't use it until resolved

Sounds like a cylinder misfire to me. Scan your computer system for fault codes. If no codes are present, you can use mode 6 data to determine which cylinder or cylinders are not contributing and diagnose and repair accordingly.

the p1400 is also an egr code more than likely the dpfe sensor differencial pressure fuel .....
common trouble with the sensor warranty was extended 2yr - 24k so could be warranty repair

It is most likely an ignition system problem so starting by replacing the spark plugs and wires ia advisable.

If the problem persists then have the ignition module, and coil packs tested.

It could be something as small Such as plugged fuel Injectors. Run a bottle of fuel injector cleaner (I use Lucas Fuel Treatment) Through the system and fill your tank with a higher grade gas and it should improve...

I’m happy to assist further over the phone at https://www.6ya.com/expert/cameron_6665f74c5d46fc23

No, just go to Autozone, they will pull codes for free.

Depending on which engine you have,this sounds like bad sparkplug wires, or a bad coilpack,if you have the 4.6 engine then you have 8 coilpacks one for each cylinder,the best way to pinpoint which coil is bad is to have the computer scanned for history codes,maybe it picked up the misfire and stored the cylinder that was misfiring, hope this helps.

Did anyone check the spark plugs and wires? Make sure the Spark plugs are the correct NGK Spark plugs, nothing else. Fuel pressure is another thing that need to be verified under a load, lke the mountain you are having trouble with.