ONE FOULED SPARK PLUG

The cap should have the number 1 next to one of the plug wires. If it doesn't, take out the number one spark plug out and turn the engine by hand until the compression stroke is felt by placing a finger in the spark plug hole. Watch the timing mark on the dampener come up to TDC. Noe look to see which plug wire the rotor is pointing to. That's #1

I think you have an ignition module which may be bad.

Take out the number one sparkplug ,use your finger and cover the number one cylinder use a remote starter and pump crank the vehicle,till compression comes out,There your top dead center,If you cant use you finger roll a ball of napkin to cover the hole of the spark plug and pump crank the vehicle till the napkin shoots out, Thats TDC ,Match the rotor to the cap number one cylinder,have the correct firing order and correct rotation,install your distributor have new marks and start the vehicle ajust timing

The cylinders are numbered 1234 starting at the front of the motor. Number four is the last spark plug closest to the firewall.

Start with a cool/cold engine.

Four cylinder: Remove spark plug wire boots (four in a row on top of the engine). DO NOT PULL ON THE WIRE only the rubber top. Make sure the wires are numbered, if not, number them. They MUST go back to the same hole they came out of after the new plugs are installed. Remove the spark plugs with a 16mm spark plug wrench. Install new plugs (any auto parts store can tell you what your options are here): Start threading the new plugs by hand so you don't cross thread the engine head by accident. Then complete tightening them gently. Spark plugs are supposed to be tightened to a specific torque: 13ftlbs in this case. If you choose to not use a torque wrench do not overtighten the plugs. Reinstall boots securely.

6-Cylinder: Remove engine cover, if present. Disconnect the six connectors on each of the ignition coils. Remove each of the six ignition coil bolts and then remove the coils by pulling straight up -- arrange them so that you know which goes back where. Remove and install the six plugs as described above. Reinstall the ignition coils with their bolts (torque: 69 in-lbs), then wires. Replace the cover.

Back: 456 Front: 123
1 links with 6 2 links with 5 3 links with 4

There may be an engine cover over the valve covers that is a big piece of plastic that may say Hyundai, or Santa Fe,

I believe its three or four 10mm retaining nuts that hold it on, take that engine cover off, and there should be 3 wires in the top of each valve cover, those big wires are the spark plug wires, and they actually connect to the spark plug which is down inside the cylinder.
To remove, you will need a 3/8 drive ratchet, a long extension, I would say 6-12 inches, long enough, but not too long, and a 5/8" spark plug socket.
Take one of the spark plug wires out, and put your long extension with the spark plug socket on it down into the hole that the big wire came out of and you should find a spark plug at the end of the tunnel.

You didn't specify whether you have the (4) cylinder or the (6) cylinder engine..... I have a 2004 Hyundai Sonata 2.4L 4 cylinder and I just changed the spark plugs in it. I believe that the 2005 2.4L engine is the same. To locate and change the (4) spark plugs on a 2004 Hyundai 2.4L 4 cylinder engine: Remove the (4) 12mm bolts from the decorative plastic engine cover. Remove plastic cover from engine and place it off to the side out of your way. Standing in front of the car, the (4) spark plugs are located laterally (left to right) in the recessed area underneath where the plastic engine cover was removed. Note: This engine has (2) coils....They are located above spark plugs number (2) and (3) from left to right. Starting with the fist spark plug on the left: Remove the spark plug cable by pulling straight up on the insulated connector. Using a spark plug socket, remove the old spark plug and install a new one in it's place. To access the second spark plug from the left, remove the electrical connector and the spark plug cable wire from coil number (1) and then remove the (2) 12mm bolts that secure the coil to the engine. Spark plug number (2) is located directly under the coil. Lift the coil straight up removing the insulated connector from spark plug number (2). Using a spark plug socket, remove old spark and install a new one in it's place. Repeat same procedures for spark plugs number (3) and (4). Note: If you have the (6) cylinder engine, the front (3) sparks pluge are readilly accessible but in order to access the (3) rear spark plugs, you will have to remove the intake manifold

If Biggy1 has described it right, I think when you remove the WIRE to the spark plug ( not the plug itself ) and oil jumps out, there is a cylindrical seal that needs replacing and one does not need to even remove the cylinder head.
I have the same problem with my corolla. On the other hand if Biggy meant when removing the SPARK PLUG oil was on the contacts....

Subaru engines (including Legacy and engines of many other automobiles, GM, etc.) have returned to so-called wasted spark ignition systems since advent of the electronic distributor-less ignition (having been used historically in early engines with magneto ignitions). With this approach, the ignition systems are less expensive and usually quite reliable. At the same time, however, a shorted spark plug (cracked or carbon clogged, etc.) (or bad ignition spark plug wire) grounds both the ignition spark and the false spark being used. This means that it also grounds the corresponding respective ignition spark of the other 180 degree out of phase cylinder (that uses the same the same coil because the spark current is connected to the spark plugs of two cylinders). Since such a defect allows more current to flow in the spark coil to two plugs when the resistance of the spark plug gap disappears due to a cracked plug, etc, it seems likely to hasten coil burn out if the spark plug/plug wire defect is not corrected before installing the new spark coil.

To explain further, wasted spark means that when a cylinder is ready to fire, it gets a spark to its spark plug while part of the spark (from the same coil and current) as a sort of copy is also sent to another cyclinder at the same time but when the piston in that cylinder is exhausting its ignited gases 180 degrees out of phase from when its spark is needed. When the second cylinder is ready to fire and receives its "spark, the first cyclinder the also receivesa "wasted" spark "copy" of the one needed by the second cylinder. Economy is achieved in manufacture because otherwise electronics would have to turn on and off four different spark coils to distribute four different sparks as needed to the four cylinders. With wasted sparks (which are cheap), because the spark current of one coil is connected (internally in the ignition coil unit) to two cylinders that are in the same position but 180 degrees out of phase in firing, the system can turn on and off two spark coils twice as fast with half the electronics and fire two cylinders that are 180 degrees out of phase. A four cylinder engine thus uses only two coils, a six cylinder engine, three coils, etc., in a wasted spark system.