2004 Dodge Neon 4 cyl Two Wheel Drive Automatic 110000 miles
my check engine light has been on for awhile. I took it to autuzone and had it scanned it showed codes 0442 and 0456. They told me it could be the gas cap I have replaced it three times and it still comes back on. My car is past due on inspection and I dont have the money to have it fixed. I need to fix it myself. I dont know anything about cars, what could the problem be?
P0442 is EVAP System Medium Leak. Replacing your gas cap may fix the problem. Did you happen to have Autozone clear the code once the gas cap was replaced? If yes, start by checking the gas cap mating area, the area where you attach the fuel hose to fill up your vehicle with gas. Check for visible damage that may cause the gas cap to not seal tight. If the area is good, go underneath the vehicle and keep checking the fuel filler hose for any leaks in the hose all the way to the fuel tank. If everything is good, check all vacuum line for your evaporative emission system.
Keep special attention on the NVLD switch.
The rest of the diagnostic requires the use of DRBII scan tool and Miller Tool #8404 Evaporative Emission Leak Detector (EELD). If the check engine light is still on (after it has been reset) and after all these have been done and corrected, you have to send the vehicle in for the smoke test to see where the leak is coming from.