Need Help Fast!!!!!!! 1992 K1500 Blazer 5.7
 

I have a truck with 99,000 miles on it. I bought it in Oct of 08. From what i can tell, it has all original parts on it. The guy that sold it to me said it sat for the better part of 2 years. This winter, It started to backfire everytime i hit the gas pedal. At first i would only do this every no and then but now it causes the truck to stall. I did notice that the exhaust smells a lot like fresh fuel. please help me. Thanks.

There are many possibilities.

I would first disconnect and remove the oxygen sensor. Run the engine and see if it runs better. If it does, your catalytic converter is plugged up.

If that does not change... Next, I would remove the throttle body and replace all of the gaskets in it. The TBI motors can leak fuel between the injector bracket and the throttle body. There is also the possibility of an EGR problem.

I had the cat removed.

Ok... How about the other stuff I mentioned?

thanks for your help... No i havent done any of that. What im trying to do is get an idea of what is going on before i put it in the shop. Im sure you know how shops can be lol. I started it yesterday and it ran fine until it got up to operating temp. Then when i hit the gas, it backfires twice and gets worse the longer the truck runs, then the truck dies