Rattling Noise

[Markwg100]

I have a 98 Jetta GL. When I rev the engine, I hear a rattling noise for the first couple of minutes I drive the car, then it goes away. It sounds like it comes from underneath the front/center of the car. I recently had the exhaust replaced, minus the catalytic converter, which the mechanic said was OK. I assumed the sound was a hole somewhere in the exhaust because I knew I had some, but it is still there. It does go away after a couple of minutes. Any thoughts?

[miro1118]

Check the heat shield on the cat.

[Markwg100]

WHat does the heat shield look like?

[miro1118]

Its metal with holes on it. Look on the cat you should see it

[Markwg100]

Thanks for your help!