Hello gloveglo 1! I am not entirely sure what you mean by C-valve but if you had code P0443 then the valve associated with that code is the evap purge valve. I'm guessing you have already had the diagnosis of the work done so assuming this is the faulty part, here is instructions for changing the purge valve which you can do yourself:
Evaporative Emission Canister Purge Solenoid Valve Replacement Removal Procedure
Important: Be sure to install a new O-ring on the EVAP purge valve.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Tighten Tighten the bolt to 12 N·m (106 lb in).