My check engine light came on. The 2 codes came back as fuel composition sensor and purge valve. My car is also blowing the fscm fuse and will not start. What could be causing that?

 

post the model year, engine and the actual code characters p00xx...maybe someone can help

 

The FSCM fuse supplies power to the Fuel Pump Flow Control Module. No power = no fuel.
Unplug the fuel pump to see if the fuse still blows. You may have a short in the fuel pump circuit that's blowing the fuse, or it's the Control Module itself that's gone bad.