I have a 2000 Hyundai Elantra. When I drive down the highway it chugs like its going out of gear or not getting fuel. I have changed the spark plugs and now changing wires. Any other ideas??

If you have done basic tune up stuff, I would check fuel pressure with gauge installed and running down the highway. Other possibles are bad ignition module, loose wire somewhere in coil circuit, bad fuel pump, filter, many others.

Yes it does. A fuel injector is a device that atomizes and then delivers the fuel into the cylinder just before the piston squeezes the fuel and air mixture and the spark from the spark plug fires. Ergo your 2000 Hyundai Elantra being a 4 cylinder vehicle, has 4 fuel injectors.

I would check the transmission fluid. It may need changed and the filter changed. Perhaps you are not getting a good spark from your spark plugs or coils. Has it been awhile since you had a tune up?

- Spark Plugs (make sure they are gaped properly)
- Spark Plug Wires
- Coil Packs (if needed) or Distributor Cap & Rotor (which ever so equipped)
- Air Filter
- Fuel Filter
- Oil
- Oil Filter
- Transmission Filter (optional)
- Transmission Fluid (optional if you do change the trans filter you will need the fluid)
- PCV Valve (optional)
- Bottle Of Fuel Injector Cleaner (add to fuel tank kind)

engine might be flooded remove spark plugs to see if they are wet with fuel pull fuel pump fuse crank eng over with plugs removssed to push fuel from cylinders dry plugs reinstall hold gas pedal to the floor while cranking untill engine starts

The biggest factor is going to be your driving habits. Slower accelerations and longer smoother stops and highway speeds closer to 55mph than 80+ will make a big difference. Of course highway driving will always be better than stop and go driving. It takes much less fuel to maintain a speed than it does to accelerate to it.
There are a lot of gimmick products out there that are exactly that, gimmicks. The biggest factor and easiest to control is the operator of the vehicle.

If your getting fuel which it sounds as though you are, check to see if your getting spark to the plugs. Sounds like an ignition system issue. Not sure about specifics on Hyundai but could be distributor cap, rotor, distributor, crank or cam shaft sensors.

The Hyundai online shop manual and my newly arrived Hyundai shop manual kept pointing to the coil as a possible problem. While preparing to check coil continuity I discovered the pigtail connected to the bottom of one of the coils was loose and the contacts were burned. This is the coil that supplies spark to plugs 1 & 4, the same ones that kept showing up each time the check engine light illuminated. After cleaning the contacts and making sure the pigtail was securely attached to the base of the coil I have had no further problems.

Check your temp sensor. sound like the ecu thinks the engine is cold and is choking the engine in an effort to warm it up.

check air filter,fuel filter,spark plugs and wires,vacum hoses for damage.with no engine trouble codes,these are the usual suspects.hope it could help!