454 Chevy engine code P0442

[charlie2]

Good evening, I have a code showing on my 2000 Chevy 454 (7.4 liter) in a 2000 Fourwinds 5000 class C. The code is P0442 Evap Emissions Control System Leak. (Small) Any ideas what might be the problem?

[smiller]

OBD-II Trouble Code: P0442 Evaporative Emission Control System Leak Detected (small leak)

[charlie2]

Smiller, Thanks for the response, sounds like I may never find it. I did put a locking gas cap on a couple years ago. I'll put the factory cap back on clear the codes and try that. will let you know if that fixes it in a about a week, have a trip this weekend.

[smiller]

These can be devilishly tough to find because the amount of leakdown considered a 'small leak' in OBDII standards is pretty small and may not be visible. Sometimes it takes a shop with specialized leak-detecting equipment to find it. But luckily it is very often due to to a defective gas cap seal and if you have an aftermarket cap that would be a good place to start.

Also note that it may take a while for the right conditions to exists for an evap test cycle to occur so without test gear about all you can do is make a fix and wait, and hope. But this shouldn't affect your trip, there's no harm in driving it this way beyond the annoyance of the check engine light.

[charlie2]

Thanks that's comforting. You always assume the worst. The good ol days with no check engine lights seemed far better.

[KIX]

A small piece of black electrical tape can help make the light disappear.

[charlie2]

It wouldn't be the first time I did that to one of my vehicles.

[wanderso]

Interestingly mine is showing P0446 on a 2001 Jamboree with the 454 (2000 year Chevy model). I reset the code and it disappeared for about 400 miles and several start stop cycles. Interestingly in both cases is that it came on within 10 minutes of a morning startup.

Since it is near end of season, I'm going to wait until spring to attempt a fix where I will be doing enough driving to see if it is fixed and any "90 day guarantee parts" haven't expired.

[charlie2]

Good luck with the Jamboree, As Smiller said they can be devilish to find.

[charlie2]

I have put the factory cap back on and cleared the code. Will travel this comming weekend and report the outcome next week.

[charlie2]

Just returned 350 miles no check engine light, Just that simple, very pleased.