Hello. Welcome to Just Answer. Please allow me to assist you with your question today. I am John, I will do my very best to help you solve this problem.
Can you upload a picture to understand better how is it printing?
Also, are you using genuine Canon cartridges? Or generic/refilled ones?
If you send a document with 6 pages, it will print pages 1, 3 and 5 only? or 2, 4 and 6?
Also, what's your operative system version?
OK. What's your OS version? Go to whatsmyos.com to find out
I want to reload your driver. Let me know the OS and I will send you a step by step procedure.
Hello, please delete the printer going to apple icon, System Preferences, Printers.
Then go here: https://www.usa.canon.com/internet/portal/us/home/support/details/printers/support-inkjet-printer/mp-series/pixma-mp490
And choose Mac OS X Snow Leopard 10.6, then download the "MP490 series CUPS Printer Driver Ver. 188.8.131.52 (OS X 10.5/10.6)"
After you download it, please install it and restart your Mac. Then try to print again.