2002 Acura RSX 4 cyl Front Wheel Drive Automatic 100100 miles

My check engine light has been coming on and off for a while and when I had a diagnostic run on it, the code for the catalytic converter came up. I was told that it was starting to go and would have to replace it soon. I ordered a direct fit converter online and a new set of spark plugs. I decided to replace my spark plugs first and after I did, the check engine light disappeared.

Can bad spark plugs cause the diagnostic to show a problem with the converter? It's hard to know how much damage the converter has taken, if any. If my converter is OK, I would like to return the one I purchased. Is this a good idea or should I replace it anyway?