1997 Chevy BLazer 4x4

Just recently when I start my vehicle it sounds like the exhaust pipe has been cut off. Then when you start to drive the vehicle and step on the accelator it sounds like a loose fan clinking noise. Any ideas?

could be/probably something to do with the cat converter. i had this problem last spring and the comb inside the converter broke, sending pieces into the exhaust. so when i fired it up, it sounded like a beast and upon accelerating would make a similar grinding/clanking noise. i would take it to an exhaust shop and have them look at it. or check the Cat yourself when it is cold.

I think bigry may be on to something here. I would check the muffler and cat to see if they are still sound.