Hello,
I have a 2007 EX-L with the I4 engine. It drives great but when I hit 60mph it starts shaking up until 65mph. Once I go above 65mph the shaking stops. I troubleshooted to see if it was at a particular rpm but it is not. It is only when I am in 5th gear and I am between 60-65mph. Also, it only shakes when I hit the gas. If I am coasting it does not shake. Any ideas on what this could be?
Also, my check engine light is on P0420 (cat or O2 sensor). Could this be the reason it happens? Could it be the tires? engine? It's weird that it only does this in 5th gear while accelerating between 60-65mph.
Any help would be greatly appreciated.
Thanks!!!!!

 

From you description, I'd think that something is out of balance on your tires or maybe your CV joints are worn.

The quickest test is to rotate the tires (front to back). If the problem goes away, then you have a tire balance issue. If the problem doesn't go away, then you want to inspect the CV joints to see if one has too much play.