So I was driving on the hwy and all of a sudden, my 07 trailblazer started to slow down, check engine light flashed, then my RPM gauge stopped working...But it never shut off.. has this ever happened to anyone? What would cause that?

 

Get the code read and you won't have to guess. That's the nice thing about obdII diagnostics.

 

That's the problem there is no code. The light flashed then went off... The RPM gauge didn't work anymore, but the truck didn't cut off.