Truck is not firing on 3 cylinders yet it runs.. Runs really rough, back fires, under powered.. Plugs are Wet, Firing order is correct. New Spark plug cables. Don't know that is wrong! Please Help

The firing order for the 2015 Subaru Forester 2.5i is 1-3-2-4. This means that the spark plugs will fire in the following sequence: first cylinder, third cylinder, second cylinder, and fourth cylinder.
The firing order of an engine refers to the sequence in which the spark plugs ignite the fuel in the cylinders. The firing order is determined by the engine's design and is important for ensuring that the engine runs smoothly and efficiently.
In a 4-cylinder engine like the 2015 Subaru Forester 2.5i, the cylinders are typically numbered from left to right, starting at the front of the engine. The firing order for a 4-cylinder engine is typically 1-3-2-4 or 1-2-3-4, with the spark plugs firing in a sequence that alternates between the left and right sides of the engine.

First have the computer scanned . Most part houses will do it for free. The miss fire codes will tell you where to look. It can identify which cylinders are miss firing or not firing at all. Identify the bad cylinders and pull the spark plugs and run a compression test on them to make sure they are ok. No compression means a problem like a burnt valve. Make sure that the firing order of the plugs are correct.

I would look into replacing the coil even though it is sending spark it might not be enough and I would go through and just double check all my wires as well as the firing order because if it's off just a little it will make the car run rough

check to see if the wires correctly. If that is ok then check to see if there inside of the distributor cap is clean and free from debris... spark will take shortest path and fire at the debris instead of the next cylinder in firing order.

Check the firing order with the firing order diagram that I have uploaded, and if that does not solve the problem then remove the spark plugs and be certain that there is an even spark plug gap between all of the spark plugs, (see the emission label under the hood for the correct spark plug gap) and be certain that there is not any split-fire or multi-fire spark plugs installed in the engine, because those plugs will not work with an OBD-II system, and a random mis-fire is the least that they will cause if installed in an OBD-II controlled vehicle.

Recheck the firing order; 1-6-5-4-3-2

On the distributor passenger side radiator to fire wall. 2-4-6-coil
On the distributor drivers side radiator to fire wall. 3-1-5

Cylinder passenger side radiator to fire wall. 2-4-6
Cylinder drivers side radiator to fire wall. 1-3-5

Good luck and also check the distributor cap again for proper seating.

Firing order on 3.1L engine is 1-2-3-4-5-6. The ignition system is a waste-spark system, which uses 3 coil packs (1-4) (2-5) (3-6). Make sure that the paired cylinders' plug wires go to the same coil pack.

that is true your firing order is wrong here is a link to a web sight that has all the 1998 explorers 6cyl just click on the one that your explorer is and it'll show you the correct firing order also make sure you have your plugs gaped right good luck.
http://autorepair.about.com/library/firing_orders/bl-ford-firing-98.htm

1991-1994 2.9L and 3.0L Engines Firing Order 1-4-2-5-3-6 1995 And Later 3.0L V-6 With DIS Ignition System Firing Order 1-4-2-5-3-6
4.0L Engines Firing Order: 1-4-2-5-3-6 DIS Ignition System