Hyundai Repair: Rough Idle- 2001 Elantra, hyundai elantra, test engine

Question
I have a 2001 Hyundai Elantra with 80,000 miles on it.  It has been running fine, no problems.  This morning I started it and it was running very rough.  I turned it off and re-started it but it is still doing the same thing.  It acts like it is "stopped up".  I can rev the engine and the idle is smooth but as soon as I get off the accelerator it goes back to "coughing".  I tried to drive it but it gets worse when I put it in drive.  The test engine light is on but, I cannot drive it anywhere to read the code.  Any ideas?

Answer
My first guess, based on the way you say the car is coughing, is that you have a misfire.  If that's the case, I'd recommend starting by checking the plugs, plug wires, and ignition coil.  

But if you want reasonably confident direction on finding the problem, you'll need to get the car somewhere that can read the codes.  If you cannot drive it, my only recommendation would be to have it towed to a local repair facility.