I finally called the factory(MTI Industries) regarding my flush mount model 60-542 CO detector. I was told that they have updated the information and it is good for 5 years from the time of retail sale. That gives me another year! They also sell the replacement that gives an audio and visual alarm when it needs replacing unlike the one I now have. (The green light just shows that it is connected and does not indicate function.)
Try as I might, I cannot upload a copy of what was sent to me. Their # is: 800.383.0269;email:email@example.com.
Hope this is helpful to those with 2009 Escapes and newer.