Ran into another problem.."check hybrid system"..

So I changed the head gasket on this 2013 Toyota Prius Hybrid recently and I'm sure you all know all that that intels..so I connect everything back (hoses, and wires). I go and start it up after putting in the fluids and it's a little bit shaky when started..then In about 20 second it just stops/turns off and says "check hybrid system pull over to safe place" and I can kinda smell gas.. if anyone could help me out or lead me the right direction, id highly appreciate it, thanx in advance