Another Check Engine Light Thread
 

I have a 2004 Pacifica with 112,000 miles. The check engine light is on, and stays on. The EGR valve has been replaced, new gas cap is on the car, and the EVAP sensor in the gas tank has been replaced. The light shut off for 24 hours after the cap and EGR valve were replaced, just long enough for the car to pass emissions testing. Now it's back on again. The car otherwise runs fine. Does anyone have any ideas?

need to know what the codes are to start with

Another Check Engine Light Thread
 

I'm being told that the code is PO440.

P0440-GENERAL EVAP SYSTEM FAILURE
When Monitored and Set Condition:
P0440-GENERAL EVAP SYSTEM FAILURE
When Monitored: Engine Running. Fuel Level greater than 12%. Ambient Temperature
between 4°C and 32°C (39°F and 89°F)
Set Condition: The PCM does not see the NVLD swtich close during the medium/large
leak test. The PCM then will increase the vacuum supply to the EVAP system by
increasing flow through the EVAP Purge valve. If the switch does not close with an
increase in vacuum an error is detected. Two Trip Fault.
POSSIBLE CAUSES
GOOD TRIP EQUAL TO ZERO
VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
VISUAL AND PHYSICAL INSPECTION
EVAP PURGE SOLENOID VACUUM SUPPLY INSPECTION
EVAP PURGE SOLENOID
NVLD SWITCH OPERATION
GROUND CIRCUIT OPEN
NVLD ASSEMBLY
NVLD SWITCH SIGNAL CIRCUIT OPEN
EVAPORATIVE EMISSION LEAK DETECTION
PCM

My mechanic is telling me that there may be a crack in a line running from the gas tank, and the trank(s) will have to be dropped to check this possibility. Does this make sense?