What can be wrong with my car

I have a 1986 grand prix with a 5.0 engine  
the problem is that after driving a while the
check engine light comes on and the car
drive sluggish like it's not going fast and
feel funny when pressing the gas pedal but
when I stop at a light a little smoke comes
from the pipes pull off a nice little cloud.
When I cut the engine off it runs on sounds
like a bunch of fireworks and I smell burned
gas that burns the nose a little how can I fix
this problem