Diagnostic code PO442

P0442 Chevrolet Evaporative Emission Control System Leak Detected Small... http://www.autocodes.com/p0449_chevrolet.html

Looks like you need a vent solenoid . EVAP Code P0449

That is an emissions code. It means you have a small leak in one of the lines. Most likely it the line that goes from the engine to the evap canister in the drivers side rear inner fender well.

A simple google search reveals this is a small leak in the emissions canister system vacuum lines. This can be as simple as a bad gas cap, or a cracked or broken vacuum hose.

if your check engine light isn't on, they will still hook up a diagnostic code tester to your vehicle to see if the computer has picked up any problems, if the computer has picked up a problem, and you fixed the problem, then you can have the code removed from the system, with a diagnostic code tester.

Obd Codes

P0305....Cylinder 5 Misfire Detected

P0442....Evaporative Emission Control System Leak Detected (small leak)

P0455....Evaporative Emission Control System Leak Detected (gross leak)

What are the codes?

http://www.obd-codes.com/p0442
http://www.obd-codes.com/p0455

Click on the links above to help you.

po442 is evap emission control system leak (small) 1 of the lines for emissions is leaking. po455 is-- emission control system leak (large). turn off light with code scanner after it is fixed.

You likely won't notice any drivability problems. P0442 indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. 
The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage.
Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

With a P0442, the most common repair is to Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back. Otherwise, replace the gas cap, or Inspect the EVAP system for cuts/holes in tubes/hoses.

Good luck and hope this helps