2003 Monte Carlo Check Engine Light

[fordboy424]

The wife's 2003 Monte Carlo SS 3.8 v-6 65000 miles all stock has been getting a p0440 (evaporative emission control). This is the first problem with the car, we have had it since new. Not really sure where to start looking. Anyone have any ideas? Thanks

By the way I have the AE domestic package, just not sure how to use all the fetures on a gas engine.

[weasel79]

I would start by checking the fuel cap. Make sure it is on tight. Then start checking the vaccum hoses and tees and anything vaccum in the engine compartment. Probably just a cracked hose or something.

[amb2958]

I'd check the intake manifold gasket as well. A lot of these engines have them fail and can cause vaccum leaks.

[Mastertech]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fordboy424</div><div class="ubbcode-body">The wife's 2003 Monte Carlo SS 3.8 v-6 65000 miles all stock has been getting a p0440 (evaporative emission control). This is the first problem with the car, we have had it since new. Not really sure where to start looking. Anyone have any ideas? Thanks

By the way I have the AE domestic package, just not sure how to use all the fetures on a gas engine. </div></div>

Evap codes can be a real PITA to pinpoint what the problem is.
I would start by looking at the evap lines where they connect to the intake manifold, then check the lines to the fuel tank from the engine compartment. Make sure none of the lines are cracked.
If you don't see anything obvious I would recommend replacing the fuel cap. Make sure to use a Delco fuel cap as I have not been impressed with the quailty of some of the aftermarket fuel caps.

[fordboy424]

I checked out her car last night started with the fuel cap and when I unscrewed it it didn't feel right like it was crossthreaded, I put it back on correctly. There is still alot of slush on the roads so I didn't climb under. Nothing obvious under the hood. We'll drive it over the weekend and see if the light comes back on. Thanks for the help.

[Going_Going_Gone]

Do a Google search on GM OBD II codes. Lots of good (and bad) info out there. Two of my sons had the same issue on Ford cars they owned and in both cases it was an electric purge valve for the charcoal canister. Bad news: dealer part only. Good news: not expensive.

[fordboy424]

Well it has been a few days and the light hasn't come back on so, I guess it good. Thanks for all the help. [img]/forums/images/%%GRAEMLIN_URL%%/grin.gif[/img]