I have a 2003 S with 54k mi. Last week while driving to CA, my CEL came on. I pulled over to have it scanned, just in case, and it was code P0442. Diagnosis was that I needed a new gas cap. So, that was installed in CA and all was fine. Then on the way home, the light came on again.

Today, I had it scanned again and the code is P0442. The dealer will look at the car next week, but implied that they might just have to take the fuel system off the car and start changing parts until they find it. Um, that sounds expensive and imprecise, especially considering the gas cap advice.

Any ideas here? I researched a bit and it seems that 'canister valves' could cause this. I don't know what that is or how much it costs.

Thanks for any insight.

 

That assembly is hidden behind the driver's rear wheel well. You can pop the wheel well liner off and look around for a broken or disconnected line. If it's not obvious that way then you may have other failures in the pump assembly (vacuum operated). There is a procedure they should be following, but here's a description of the CEL:

Evaporative Emission System Leak Detected (small
leak)
Diagnostic conditions
• Battery voltage between 10 V and 16 V
• Engine must cool down by at least 42 °K in the time that elapses
between stopping and restarting engine
• Intake air temperature between 5 °C and 95 °C
• Variations of intake air temperature less than 12 °K
• Vehicle is travelling with longer partial load share (3 - 150 km/h)
• Engine temperature higher than 5 °C
• Diagnosis only runs below 2400 m above sea-level
• No P0441, P0444, P0445 (EVAP canister purge valve) or
P0446, P0447, P0448 (EVAP canister shutoff valve) faults in
memory
• No P0455 tank system (major leak) fault in memory
• No P2400, P2401, P2402 (leakage diagnosis pump) fault in
memory
• No P2403 and P2404 (reed switch) fault in memory
Possible cause of fault
♦ Tank cap not tightened correctly or faulty
♦ Mechanical fault in EVAP canister purge valve (does not close
fully)
♦ Leakage diagnosis pump leaking internally (membrane) or externally
♦ Mechanical fault in EVAP canister shutoff valve (does not close
fully when power is supplied)
♦ EVAP canister shutoff valve connections leaking
♦ Tank system (including pipes) leaking

 

Thanks - that's a great start. I'll post when I figure it all out here.

 

good info that Mrhead..deserves a rep point i think.

 

the dealership should have a smoke detection machine, which allows us (technicians) to easily spot a gas vapor leak, large or small. If they claim to not be in possession of this machine, run, to another dealer or indy shop. Not only does the machine save lots of time, it avoids the guessing game they want to play with your $$$$$$$$$$$$$$$

 

Coincidentally, I had a P0441 code that has turned out to be a stuck valve on the EVAP canister. They are replacing it under CPO warranty.

 

Any idea what that costs when one does not have a CPO warranty?

 

It was about $500 due to the amount of diagnostics checking multiple lines going from the engine compartment to the valve assembly and gas tank area. The part itself is about $200, so I'm told.

 

going through Vacuum Smoke Test now on my 2006 base......thought it was a belt going loose but indy shop says belt is fine and only error code they have seen is for Vacuum leak.

I wonder "what" is leaking in the engine..........

 

Before getting carried away tearing apart the carbon canister and lines,etc I would start with checking the tank vent valve located on the engine. These can fail after a period of time, and can stick open, not holding vacuum. I you pop the "4.5 V8" cover off, it is on the right side with a small connector and a vacuum line going to it. It vents what is collected in the canister into the engine, and can cause "Incorrect purge flow" fault codes. It runs along the drivers side of the intake manifold and connects at the back near the secondary air pump. Pop the clamp and line off, put a vacuum gauge on it, and see if it holds, or leaks. Sounds like you will have an answer quickly, as frequently as this is happening.

 

Ok, the indy shop identified the part but didnt tell me what it was after the smoke test. They quoted me $360 for smoke test, replacing the part that is failing, and power steering flush since that code had fired.......Im at 107k miles and need to do it I would imagine.

Not too bad on price....since I lacked tools and knowledge.