Does anyone know why my exhaust is popping and why is it smoking

 

back fire is often caused by then induction of air into the exhaust system

a little bit of unburned fuel, exhasut leak and hot exhaust pipe and boom ya got yourself a back fire.

as for the smoke what does it look like blue, white, black etc.

 

anywhere from a light white to a medium grey depends on how long its been running

 

it could be burning antifreeze, have you been goin through coolant lately