Check Engine Light
Thread Starter
Safety Car
Joined: Dec 2002
Posts: 4,869
Likes: 2
From: San Diego CA
Check Engine Light
I have a 2003 coupe with approximately 40,000 miles. The check engine light came on yesterday with no discernible change in performance. I ran the codes on the DIC and the only thing I came up with was P0442 HC on the PCM. There were also a couple radio codes and 2 codes each for the LDCM and RDCM which I would doubt are relevant.
Any ideas why I would get a check engine light with only one historic code?
Thanks for any thoughts you might have.
Any ideas why I would get a check engine light with only one historic code?
Thanks for any thoughts you might have.
Burning Brakes
Joined: Mar 2010
Posts: 1,189
Likes: 4
From: Freeport, FL
Make sure you are searching P zero four four two. It is not the letter 'O'
What does that mean?This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
SymptomsYou likely won't notice any drivability problems.
CausesA code P0442 most likely means one or more of the following has happened:
A loose or improperly affixed gas cap
A non-conforming gas cap (i.e. not factory/original brand)
A small leak/hole in a fuel vapor hose/tube
Other small leak in EVAP system
Faulty vent o-ring seal
Possible SolutionsWith a P0442, the most common repair is to:
Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
Otherwise, replace the gas cap, or
Inspect the EVAP system for cuts/holes in tubes/hoses http://www.obd-codes.com/p0442
What does that mean?This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
SymptomsYou likely won't notice any drivability problems.
CausesA code P0442 most likely means one or more of the following has happened:
A loose or improperly affixed gas cap
A non-conforming gas cap (i.e. not factory/original brand)
A small leak/hole in a fuel vapor hose/tube
Other small leak in EVAP system
Faulty vent o-ring seal
Possible SolutionsWith a P0442, the most common repair is to:
Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
Otherwise, replace the gas cap, or
Inspect the EVAP system for cuts/holes in tubes/hoses http://www.obd-codes.com/p0442
Thread Starter
Safety Car
Joined: Dec 2002
Posts: 4,869
Likes: 2
From: San Diego CA
That is interesting. I noticed a strong fuel odor in the garage today. The check engine light came on during my return trip. I stopped for fuel. It remained on. Then today I noticed a strong fuel odor in the garage. I wonder if there is a leak in the fuel line somewhere.
Race Director
Joined: Jul 2004
Posts: 16,794
Likes: 62
From: Lake Havasu City, AZ
If it is a loose cap it will take about 5-6 on-off cycles with the car getting to operating temperature and cooling down to go away on its own.
Of course you can manually clear the code remove /tighten the cap and see if it comes back.
Of course you can manually clear the code remove /tighten the cap and see if it comes back.
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Thread Starter
Safety Car
Joined: Dec 2002
Posts: 4,869
Likes: 2
From: San Diego CA
Cleared the codes and drove it about 50 miles without a return of the CEL. With all the weather it had been sitting for about 3 weeks with a nearly empty tank (usually I try to keep the tank nearly full when sitting). I don't know if that had anything to do with it, but it seems to be ok for now. Thanks for all the advice.
4th Gear
Joined: Sep 2010
Posts: 4
Likes: 0
From: Atascadero CA
Corvette Forum has saved me Many $$$ again
SO far this forum has saved me a minimum of 1600.00!!
First it was the dimming HVAC Temp light, then the Service Column Lock, now this P0442 HC.
That code was not on the list I got from the previously mentioned web site, however, after reading this tread, went out , checked the gas cap O-ring and sure enough, cracked from age. To test it out, wiped a thin film of oil on the cap and tightened it tight. Cleared the code and the Check Engine Light gone, did not re-occur.
Hopefully Chevy wont charge me tons for the new O-ring to make up some of the difference.
Wish I had known about it when the engine light came on the first time and the dealer charged me more than I care to share to clear what was probably a bogus diagnosis.
I am eternally grateful to this site, its members and the contributors.
Rviar
First it was the dimming HVAC Temp light, then the Service Column Lock, now this P0442 HC.
That code was not on the list I got from the previously mentioned web site, however, after reading this tread, went out , checked the gas cap O-ring and sure enough, cracked from age. To test it out, wiped a thin film of oil on the cap and tightened it tight. Cleared the code and the Check Engine Light gone, did not re-occur.
Hopefully Chevy wont charge me tons for the new O-ring to make up some of the difference.
Wish I had known about it when the engine light came on the first time and the dealer charged me more than I care to share to clear what was probably a bogus diagnosis.
I am eternally grateful to this site, its members and the contributors.
Rviar