I have a 91 SE and whenever I turn the car off after it has been run for about 5 minutes at least, there is a loud clicking noise coming from the engine. I have heard it once while the car was on at idle afer being driven for a while, and last night when I was pulling in my mom said she could hear the clicking while I was driving up the road, but I started it back up and had hr rev the engine a bit and nothing abnormal. The clicking goes on for about 2 minutes after the car is shut off. Anybody have any ideas?

 

I think you're describing two different things:
1) When your car is running the heat shield under the Catalytic converter is probably rattling
2) When you shut off a car, the exhaust is still really warm, as it cools down it will make a popping or crackling noise, it's normal.

 

Would this indicate any problem with the exhaust studs?

 

Not if it's just the pipes cooling. I know worn exhaust studs make noise and they're expensive, but I don't know what kind of noise they make, I really don't have any experience with these. Is it a rhythmic clicking, as in a specific frequency? If it's random with varying volume, then it's just the pipes cooling, if it's rhythmic then it's a mechanical problem. That's about all I can help you.