Its Back....Check Engine Light Code P0442
Thread Starter
Melting Slicks
Joined: Mar 2007
Posts: 2,600
Likes: 305
From: Carmel Indiana
Its Back....Check Engine Light Code P0442
Well, thought had the check engine light issue fixed by replacing the gas cap. Cleared all the codes and was good for about 3-4 engine start cycles.
Now check engine light is back with new code P0442 - Evaporative emission system small leak detected, PCM engine controls.
got this code after a short trip and before I shut the engine off. With a new gas cap, what would the next thing be to look at ???
Now check engine light is back with new code P0442 - Evaporative emission system small leak detected, PCM engine controls.
got this code after a short trip and before I shut the engine off. With a new gas cap, what would the next thing be to look at ???
Drifting
Joined: Jun 2013
Posts: 1,960
Likes: 342
From: Shell Point (Crawfordville) Florida
Is that code H or C?
You said you cleared the code after you replaced the gas cap. You put the gas cap on tight, it clicked and all that? Have you checked it to see if it's loose?
Did you get a genuine GM OEM Corvette cap? When I just replaced mine, the dealer gave me a cap that fit fine, but it was made in Germany. I haven't had any problems with the light coming back on in 2 months and 1500 miles of driving since the new cap.
You said you cleared the code after you replaced the gas cap. You put the gas cap on tight, it clicked and all that? Have you checked it to see if it's loose?
Did you get a genuine GM OEM Corvette cap? When I just replaced mine, the dealer gave me a cap that fit fine, but it was made in Germany. I haven't had any problems with the light coming back on in 2 months and 1500 miles of driving since the new cap.
Thread Starter
Melting Slicks
Joined: Mar 2007
Posts: 2,600
Likes: 305
From: Carmel Indiana
Is that code H or C?
You said you cleared the code after you replaced the gas cap. You put the gas cap on tight, it clicked and all that? Have you checked it to see if it's loose?
Did you get a genuine GM OEM Corvette cap? When I just replaced mine, the dealer gave me a cap that fit fine, but it was made in Germany. I haven't had any problems with the light coming back on in 2 months and 1500 miles of driving since the new cap.
You said you cleared the code after you replaced the gas cap. You put the gas cap on tight, it clicked and all that? Have you checked it to see if it's loose?
Did you get a genuine GM OEM Corvette cap? When I just replaced mine, the dealer gave me a cap that fit fine, but it was made in Germany. I haven't had any problems with the light coming back on in 2 months and 1500 miles of driving since the new cap.
Clicked it good, several times. The code came back as C then HC. I've cleared all the codes again, but the light is now staying on all the time. last time at least the light went out for 3-4 starts.
Pro
Joined: Jan 2016
Posts: 550
Likes: 53
From: Fort Myers Florida
Yep, the cap came from GM dealer in a GM plastic bag, but I have no clue where it was made. It had the same model number as the one sold by Gene Gulley, so I guess it was for the vetter, rather than a Malibu or something.
Clicked it good, several times. The code came back as C then HC. I've cleared all the codes again, but the light is now staying on all the time. last time at least the light went out for 3-4 starts.
Clicked it good, several times. The code came back as C then HC. I've cleared all the codes again, but the light is now staying on all the time. last time at least the light went out for 3-4 starts.
Thread Starter
Melting Slicks
Joined: Mar 2007
Posts: 2,600
Likes: 305
From: Carmel Indiana
I had the same problem even with a new gas cap. I fixed it by looking at the cap and not making it click when I turn it. I look at the cap and the way it goes on the filler and only turn it about 1/2 inch and it is snug. After doing that I only see the CEL if I forget to follow my own instructions and tighten it til I hear it click.
I'm also going to do the carb cleaner and WD-40 in the air pump hose/check valve trick even though the code is not related, anything to get rid of the CEL. Things like that just bug the H out of me to look at !!
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Look on the drivers side of the engine. There is a vacuum nipple just rearward of the throttle body/manifold neck. There's a plastic fitting that has a hard plastic line that goes to a electronic solenoid after the solenoid is a plastic corrugated hose.
Those hoses have a tendency to crack and or break. That's the vacuum line and solenoid for the Fuel Tank EVAPORATIVE CANISTER System.
If that hose of pipe has a vacuum leak it will throw the same DTCs.
You can see the plastic corrugated hose on the drivers side at the rear of the engine:
Better picture of the hose:
Those hoses have a tendency to crack and or break. That's the vacuum line and solenoid for the Fuel Tank EVAPORATIVE CANISTER System.
If that hose of pipe has a vacuum leak it will throw the same DTCs.
You can see the plastic corrugated hose on the drivers side at the rear of the engine:
Better picture of the hose:
Thread Starter
Melting Slicks
Joined: Mar 2007
Posts: 2,600
Likes: 305
From: Carmel Indiana
Well I checked the fitting/line mentioned by Bill C and it "looks" Ok. However, not sure how a positive check of a vac line can be done other than visually. Not like you can spray soapy liquid on it and check for a leak like tire leak
On a positive note, I did do the gas cap trick of attaching it, rotating about 1/2", but not waiting for the clicks. The wife then went out for some errands and she said the CEL went out. Its now been out for 3-4 cold starts so. . . . we shall see.
On a positive note, I did do the gas cap trick of attaching it, rotating about 1/2", but not waiting for the clicks. The wife then went out for some errands and she said the CEL went out. Its now been out for 3-4 cold starts so. . . . we shall see.
Drifting
Joined: Jun 2013
Posts: 1,960
Likes: 342
From: Shell Point (Crawfordville) Florida
Get a new gas cap - that one doesn't fit correctly making a tight seal when the cap is put on properly. By not clicking it on, you are risking having it come off while you are driving.
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Pro
Joined: Jan 2016
Posts: 550
Likes: 53
From: Fort Myers Florida
Well I checked the fitting/line mentioned by Bill C and it "looks" Ok. However, not sure how a positive check of a vac line can be done other than visually. Not like you can spray soapy liquid on it and check for a leak like tire leak
On a positive note, I did do the gas cap trick of attaching it, rotating about 1/2", but not waiting for the clicks. The wife then went out for some errands and she said the CEL went out. Its now been out for 3-4 cold starts so. . . . we shall see.
On a positive note, I did do the gas cap trick of attaching it, rotating about 1/2", but not waiting for the clicks. The wife then went out for some errands and she said the CEL went out. Its now been out for 3-4 cold starts so. . . . we shall see.
Pro
Joined: Jan 2016
Posts: 550
Likes: 53
From: Fort Myers Florida
if he turns it a half turn there should be no way it comes off, unless the rubber seal itself is broken or no good. I bought a new cap to replace the one I thought was not sealing and it had the same issue, brand new GM cap I overpaid for lol. It might be my filler neck so when i get a chance I am going to smooth it out a little.
Thread Starter
Melting Slicks
Joined: Mar 2007
Posts: 2,600
Likes: 305
From: Carmel Indiana
I made sure the filler neck was clean and doing the 1/2" turn without clicking is still working. We just came back from 4 day trip, about 400 mi. and never saw the CEL so must be something to the "don't over click" a new cap method.
Last edited by jdsaengine; Jun 13, 2016 at 11:05 AM.
thanks for the update and hope you have many more trips...
Pro
Joined: Jan 2016
Posts: 550
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From: Fort Myers Florida
Advanced
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I had the same problem even with a new gas cap. I fixed it by looking at the cap and not making it click when I turn it. I look at the cap and the way it goes on the filler and only turn it about 1/2 inch and it is snug. After doing that I only see the CEL if I forget to follow my own instructions and tighten it til I hear it click.
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if I wasn't mechanicaly inclined this car would have been burned 15yrs ago
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