2004 cavalier check engine code PO446 - 2004 Chevrolet Cavalier

SOURCE: 2000 cavalier check engine light code po440

P0440 - Evaporative Emission (EVAP) System


evaporative emission (EVAP) system has a large leak.
Check the gas cap or vent valve. these are the most common problems.


The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the Fuel tank pressure sensor (FTP). When the sensor indicates a small leak in the EVAP system, this code is set.


Here are some additional causes.

* A small leak in any of the EVAP hoses or fuel tank hoses
* A small leak in the purge valve or vent valve
* The EVAP Canister may be leaking

SOURCE: 2006 chevy cobalt code po446= check engine light

Check Engine light must be reset with a scan tool. If the problem has been repaired the light can be reset. Some parts stores will check and reset for free, otherwise it will have to be taken to a shop where they may charge a fee to check and reset it for you.