After removing my catalytic converter and replacing it I now have a no crank no start situation what can cause that the motor is turning or making a spinning sound but no crank

 

I'd double check connections. O2 sensors and maybe the trans connectors. Can't really think of anything else assuming nothing else was touched.

 

Definitely check O2 sensors. May have flooded the engine as well. Try the deflood procedure once you identify if there were any reinstallion issues.

 

Engine spinning = cranking, so I'll assume from the description that it's doing that but not firing up. I would check for flooding first, pull the spark plugs, see if there's is fuel on them and clean it off if so. Reinstall and perform the deflood procedure (you can google the details).

It's not the O2 sensors, they're not active during startup.

 

How healthy is your starter? Was anything tampered with that recently, check connections just trying to help you cover all basics.

 

I'm with the above on check the wiring for connectors that are not secure. The only wiring that is touched during that job is the connector for the oxygen sensor. Do some due diligence and check the trigger wire on the starter to ensure its clean and tight as well.

 

Was there an check engine light on before you changed the cat? You may have waited too long to replace it. Have a proper rotary compression test done. These engines and cats sometimes both pack it in at the same time.