I have a 97 Honda Civic EX with a bad automatic transmission. and I have a 94 Honda Civic automatic transmission are they interchangeable

 

I think fit wise it will bolt up, assuming they're both D series. Electronics will be different though. Take a look at the connections for both trans. Do they look different?

No desire to pop in a manual trans?

 

You have a 97 honda civic ex automatic, you also have a 94 honda civic automatic, do the oem part numbers match on the honda oem parts site?

 

No, it will not work as a direct replacement alone.