Toyota Repair: Corolla exhaust manifold glowing orangey red, toyota corolla, engine misfire

Question
I have a 1993 toyota corolla I have noticed when I run the car on the Turnpike the exhaust flex pipe is glowing an orangy red. I am unsure what could be wrong with this. Thanks for any help in advance  

Answer
There are a couple of things that could cause this condition, there may be an exhaust leak before the catalityc converter, check for a cracked exhaust manifold.
There may be a malfunction with the engine causing it to run way too lean, possibly an engine misfire.
The engine may be running too rich and in combination with an exhaust leak cause combustion to take place in the exhaust pipe.
The ignition timing could be out of adjustment.