W i start my 2000 gallant it idles real rough put in drive knocks and bangs when you go?

A rough idle and knocking when putting your 2000 Gallant in drive could indicate several issues, including a faulty engine mount, transmission problems, or engine misfires. It's also possible that there could be a problem with the fuel system or ignition components. To diagnose the issue accurately, it's best to check for any error codes and inspect the engine and transmission components thoroughly. If you're not familiar with car repairs, consider taking it to a mechanic for a professional assessment.