It starts very good and runs fine, then the check engine light comes on and starts to flash on and off, then puffs of smoke start to come out of the muffler, then a big spark, it looses it's speed and power, it does it for a while, then it stopes smoking and takes of like a bat out of hell and all is fine ?

What do you mean by "a big spark"? Are you seeing a flash of light somewhere? What color is the smoke?

The spark, is a flame coming out of my exhaust, and the smoke is black

Stop driving your vehicle before you damage something else. Have it towed to a garage where they can run the proper tests on it. There should not be flames coming out of your exhaust, ever.

It sound like the engine is dumping fuel in excess and it is igniting in the exhaust.
A flashing check engine light means that damage is being done to the catalytic converter.
Have the vehicle towed to where it can be diagnosed. Do not drive it.