The design keeps fuel vapors from the fuel tank, throttle, and intake box in a storage container. The EECS uses a charcoal-filled canister with hoses connected to capture and store fuel vapors from the fuel tank, directed by vacuum from ported and intake vacuum systems. The system stores fuel vapors in the car's canister when the engine is off, and starts using them by opening a valve to draw them from the canister when the engine is running. When the purge control solenoid doesn't work, a damaged canister, or torn hoses can make the car idle poorly, stall at times, or drive poorly. Lost gas in the system or bad smells suggest fuel lines, the canister, or vapor or control hose components are broken. We need to check each hose for bends, holes, and splits, and look for any damage to the canister. When fuel leaks from the canister, the whole unit needs to be replaced, plus you need to check the hoses. The lower tube of the purge valve assembly gets connected to a short hose to see if air can pass through, and a vacuum pump checks for leaks in the purge control solenoid. The first step to check for a problem is to place a vacuum pump on the solenoid valve. If it immediately shows leaks, get a new solenoid to fix the issue. However, if it holds vacuum, attaching 12 volts from a vehicle battery should let fuel vapor pass into the intake. The canister underneath a vehicle must be carefully positioned on jackstands. Remove all vacuum lines and free the clamp that holds the canister before disconnecting, and re-installation follows this sequence in reverse.