Does your Cox remote look like one of these: [Link: urcsupport.com]?

If so, click just below the image of your Cox remote and follow the instructions to blink back your setup code.

The Vizio remote uses the same setup codes as the Cox remotes pictured in the above link, so you can just enter it into the Vizio remote.

I'm betting on 01877.  Since you've already tried 01877 with the Vizio remote, please make sure that the Vizio remote blinks twice after you setup this code.  Oh, and make sure you're setting it up on the cable device button. :)