you will find the canister on the right side inside the front bumper just remove the plastic splash guard inside the wheel well
P0441 Evaporative Emission Control System Incorrect Purge Flow
evaporative emission control sytem purge control circuit malfunction
Evaporative Emission System Incorrect Purge Flow
check your charcoal canister, or evaporative purge system for a broken or missing vacuum line
Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Trouble code P1444 means: Evaporative Emission System Purge Flow Sensor Circuit Low Input
Generic codes P0440 Evaporative emission system malfunction P0401 Exhaust gas recirculation system Insufficient flow detected.
Trouble code P0455 means: Evaporative emission (EVAP) control system leak detected (no purge flow or large leak)
Trouble code P0455 means: Evaporative Emission System Leak Detected (gross leak/no flow)
The carbon canister in the 99 Elantra is in a plastic case mounted to the frame just behind the driver's side rear tire. There are fuel vent line entering it and there is also an electric line that connects to an emission sensor.
It's an evaporative emission system leak. Usually kicked off when the gas cap is not secured after refueling. It will show up usually after the engine has cooled and restarted the next day.
A good condition 1999 Eclipse is worth about $3,500.00