i got a 92 sc400, when i’m at a complete stop my car idles rough and once i start driving the cat jolts really bad, it also shuts off when going to a stop. please help if you have any clue what the issue could be! (battery is new, got the starter and alternator tested all passsd)

 

You could have a few things going on here. Do you have a check engine light? If so, you can search how to diagnose your CEL on that car since it's OBD 1. There's a series of "flashes" it will give you that can help forum members further diagnose your issue.

 

What Rudy said, maybe a little more information would be helpful cause honestly it could be anything from a sensor to a fueling/spark issue.