its connected to the fuel tank, so mabe the fuel pump?

and is that white thing where the fuel sending unit is located?

 

That is the charcoal canister, used for storing evaporative fuel vapors. The engine will purge this canister periodically during operation.

 

The black box is for the fuel evap system. My brothers went out on his 98 and was a $75 GM only part if I remember right. We had hell trouble shooting it, no codes and would idle like crap (to the point of stalling) only when the motor was warmed up.

 

I have gas leaking out of the EVAP Purge Valve. Any way to find out if this Charcoal canister is bad in my 98 Blazer?