2000 Hyundai Elantra

Engine problem
2000 Hyundai Elantra 4 cyl Front Wheel Drive Manual 121000 miles

My car suddenly started running very sluggish, and iddling very rough. The engine temperature indicator is in the normal operating range but my exhaust manifold was glowing red after about a 15 minute drive. The exhaust at the tail pipe smells rich and does not exit smoothly. It sounds like a cylinder is missfiring, but I only hear this at the rear of the vehicle. I replaced the O2 sensors about 5,000 miles ago. Is this an ignition problem or is the exhaust clogged?
January 13, 2008.

It's most likley a partially clogged converter.

Jan 13, 2008.
No I don`t think so, I haved that same problem last week, I have an elantra 2000, the problem was the wiring ofr the sparkplugs, what happen is since the ignition is not working properly, the gas accumulate in the catalytic converter and starts to glow red, that was the remedy for my problem

Feb 6, 2011.