I also doubt the specs are different. However, from what I understand the US has different emissions regulations per state wheras Canada's is pretty much the same everywhere. Also, when I was on this website looking up parts (rockauto.com) I found that some parts had US flag or Canadian flag beside it (sometimes both flags). So I phoned them up and they said that some of the Mass Airflow Sensors were for US market only (the Hitachi's were US only). They sold some "CarDone" MAF sensors to the Canadian market....i'm so confused....
But long story short, on one of my other threads I mentioned my recent MAF problems. So I bought one used and it was garbage...I think I'm going to just stick with dealer parts for electrical but I dont want to pony up $330 right now....sigh