Possible causes for P0440 on a 2002 Camaro could include:
* Loose or damaged gas cap: This is the most common and easiest to check first. Ensure the gas cap is properly tightened and not damaged.
* Leaks in the EVAP system: Cracks or holes in hoses, lines, or the canister itself can cause this code. A visual inspection is needed, often requiring access under the vehicle.
* Faulty EVAP canister: The canister is where fuel vapors are stored temporarily. It can become clogged or fail.
* Problems with the purge valve: This valve controls the flow of fuel vapors from the canister to the engine for combustion. It may be stuck open or closed, or malfunctioning.
* Faulty EVAP vent valve (sometimes called a pressure sensor): This valve regulates pressure within the fuel tank and the EVAP system. A malfunctioning valve can cause inaccurate readings leading to the code.
* Faulty EVAP system pressure sensor: This sensor monitors the pressure in the EVAP system and sends data to the computer. A faulty sensor can cause inaccurate readings.
* Faulty PCM (Powertrain Control Module): While less likely, a problem with the car's computer itself could be the root cause. This is usually diagnosed by elimination of other possibilities.
To diagnose the problem:
You should start by checking the gas cap and ensuring it's securely tightened. If the problem persists, a professional mechanic will need to perform a more thorough inspection, possibly using a scan tool to access more detailed diagnostic trouble codes and monitor system pressures. They'll check all components mentioned above. A smoke test of the EVAP system is often performed to locate leaks.
