sport trac losing power and smoking out the tail pipe, smell like gas buring

What is your question?

the sport trac just started a large amount smoke from tail pipe and has lost power while driving. it smells like the gas is going through the pipe. as soon as i slowed the engine would cut off. it restarted but i had to keep gas pedle to floor, most i could get for speed was 30 miles hr. i traveled 10 miles and used ablout 20L of gas. it seems like the gas is just going out the tail pipe. what would cause this?