Good afternoon, everyone. My name is Cinnamon. I'm a newbie to this board. Recently, in my 99 Mitsibishi Mirage, my engine light came on. When they ran the computer check, I got a code saying "PO442 Evap sys leak (small)". Well, we just went through a hurricane, and it's hard for me to track down the guy that was gonna check the car out. They cleared the code, but I was wondering if anyone knew what this code really means. Is it serious? Is it cool for me to still be driving around? Also, I was wondering if, once they clear a computer code, if the problem is still there, won't the code come back up again?Lastly, does anyone know of an online source where I can look up computer codes? All the searches I've done have only come up with books I can purchase.
Any help would certainly be beneficial.

Cinnamon

 

When your car is parked, the vapors from the gas tank getting hot and cold from the weather are collected in the charcoal canister, it absorbs fumes. When the motor is started, a solenoid opens to put all the EVAP and charcoal air into the manifold. Then once the motor is warmed up, another solenoid opens, that lets engine vacuum suck air in from the charcoal canister. Anyway, the more restrictive ODB2 settings for 97+ cars, they put a pressure sensor in the EVAP system, thats supposed to signal the ECU when it sees the EVAP go under vacuum, so it knows that the solenoid is opening and the hoses are still hooked up.

Thats what causes your check engine light and code PO442 Evap sys leak to trigger. There could be a crack in the plastic of your charcoal canister. A hose could be pulled off, or broken, or split, or removed by a mechanic and never put back on. The pressure sender could be broken and never signalling the ECU. The solenoid could be broken and never performing the EVAP purge. Any of the wires to the solenoid or the sensor could be broken, shorted, or unhooked.

It could be all that OR LOL....your gas cap might not be sealing properly or you just didnt put it back on tight. In either case....the code would need to be cleared by the code scanner and regardless of the problem, the code PO442 Evap sys leak.....is safe to drive under.....(in my opinion)

 

When your car is parked, the vapors from the gas tank getting hot and cold from the weather are collected in the charcoal canister, it absorbs fumes. When the motor is started, a solenoid opens to put all the EVAP and charcoal air into the manifold. Then once the motor is warmed up, another solenoid opens, that lets engine vacuum suck air in from the charcoal canister. Anyway, the more restrictive ODB2 settings for 97+ cars, they put a pressure sensor in the EVAP system, thats supposed to signal the ECU when it sees the EVAP go under vacuum, so it knows that the solenoid is opening and the hoses are still hooked up.

Thats what causes your check engine light and code PO442 Evap sys leak to trigger. There could be a crack in the plastic of your charcoal canister. A hose could be pulled off, or broken, or split, or removed by a mechanic and never put back on. The pressure sender could be broken and never signalling the ECU. The solenoid could be broken and never performing the EVAP purge. Any of the wires to the solenoid or the sensor could be broken, shorted, or unhooked.

It could be all that OR LOL....your gas cap might not be sealing properly or you just didnt put it back on tight. In either case....the code would need to be cleared by the code scanner and regardless of the problem, the code PO442 Evap sys leak.....is safe to drive under.....(in my opinion)