engine code p0442

code p0442 able to clear but comes back after a few days.any ideas.?

P0442

Evaporative Emission (EVAP) System Small Leak Detected

This DTC will detect a small leak in the evap system between the fuel fill cap and up to the purge solenoid.

try replacing your fuel filler cap.

what year vehicle? I have a 2004 and this is what this code is for. not sure if its different for other years.

mine is a 2000 Venture, was able to clear the code and than after filling seems to come back...so I am going to look in to the cap thanks..

Before you change your cap, look at the seal and make sure it is intact and not cracked. Also look at the filler neck and make sure there isn't any rust on it. Also, a little bit of vaseline on the seal and filler neck will seal it enough to test for a week or two. The evap leak test won't run with a full tank of gas, It has to be between 3/4 and 1/4. If the code comes back after vaselining the filler neck and cap then you probably have a leak somewhere else.

I have replaced the fuel cap and cleared message but came right back...any ideas where else I can look for this leak.....thanks.

Yes, every line that has to do with the evap system. A common area would be the fuel filler neck itself. If it is rusted through (starting to) you will get the slow leak first, then a gross leak. Without a smoke tester you will be just looking at everything you can see to make sure it isn't rusted. Also, the evap vent solenoid itself can leak and give you the code. These are generally the most difficult to diagnose without the smoke machine.

Even more common is the connector that runs from the EVAP tank and the fuel tank to the ecm. Look up at the underside of the floor pan approx. where a passenger behind the driver would put their feet. There should be a removable 8pin or so connector nearby. That connector handles the fuel gauge, fuel pump and evap canister wiring.

It goes bad. Unplug it and look over the pins for corrosion. This is a common fault on 99-05 vans and will set the evap code among other things.
It takes only a moment to check it out by inspection.

Check out my reply to thread "1999 Evap trouble 0440 and 0442"