Obd system-diagnostic trouble code present p0442 p0455?

Answer 1

P0442 is an Evaporative Emission Control System Leak (a small leak) ("EVAP") The sensor is indicating a fuel vapour (US spelling "vapor") in the EVAP system. It means a small leak has been detected. Apparently the leak can be a hole as small as 0.04" in diameter. The EVAP control system prevents the escape of fuel vapours from a vehicle's fuel system. Fuel vapours are routed by steel tubes and neoprene rubber hoses to a charcoal cannister for storage. Later a purge control valve opens allowing the fuel vapours to be sucked into the intake system of the engine. The problem is not likely to cause the engine to operate any differently. The most likely cause is a loose or poorly fitting gas cap. Other possible causes are: a non-conforming gas cap, a small leak or hole or crackin a fuel fuel vapour hose or tube, a small leak elsewhere in the EVAP sustem or a faulty vent o-ring seal, or a faulty sensor. The most common repair is to remove, inspect and reinstall the gas cap, clear the code and drive to see if the code reappears. Replace the gas cap. Inspect the EVAP system for cuts, holes, cracks in the tubes and hoses. A smoke test is helpfull in detecting non-visible holes. Patience is also helpful. Steel tubes can rust out as a result of salt and water exposure and neoprene rubber can become brittle with exposure the UV light and Ozone. Donald Partridge 2123 Prince Charles Road Ottawa, Ontario, Canada