Shakes when started and 1st gear

Hi,
i noticed this problem on the jeep a few months ago. when i start the jeep the car kinda rattles and shakes. Then everytime i go from a stand still in first gear the car does the same things....this little rattling sound. It sounds like it is coming from the bottom center of the car under the gear shift. Also, when i shut the car off the sounds is heard. When the car is driving on a constant rpm everything seems to be fine. It sjust when the car is shaking or something, the sound is heared. Possibly a heat shield? Any advise would be greatly appreciated. Thanks

Check out the catalytic converter. Sometimes the honycombe inside breaks up and will rattle around eventually plugging off the exhaust.

If it is the cat, find an aftermarket one - way less money than the jeep part.

JD

I'm having the same problem with my 97 and I was wonering if it is the cat?

JDPascal had the right suggestion.
Check out the catalytic converter.
This was actually a recall and was replaced at no cost at the dealer.
It was a 95 but even if your year is different I would check it out.

I've also got a 97 with the same problem and have replaced the cat prior to this rattle and shake. It also rattles when I hit a bump. I've replaced the front shocks and am now starting to suspicion the motor mounts or transmission mount.

My 97 high-mileage 4 cylinder developed this rattle after replacing the cat and muffler. I took it back to the shop after I found the front hanger broken. They fixed that and the rattle soon came back.

I thought my motor mounts or tranny mount was bad. But after looking it over again, I discovered that the front and rear muffler hangers were not holding the muffler high enough so it would bang on the tranny skid plate. Replaced the rear hanger and tweaked the front one..... No more rattle! Boy, do I like driving my Jeep once again!