Oh wise CL members, can someone please tell me about code: PO441 and PO446. My sc would thank you, as do I.

 

This is a site that gives you potential reasons for each code: http://www.obd-codes.com/. Perhaps someone with experience can pin point the cause.

 

Okay ... both trouble code deal with the emission system. That begins with gas cap. If I remember correctly you got a new gas cap. Now was a OEM cap. The system gets pressurized so the cap must fit correctly otherwise it will leak.

Next there are vacuum lines, a vapor pressure switch, and sensor. 441 and 446 errors are recorded in the ECM when there's a leak or malfunction within the system, i.e. switch, valve or sensor.
Problems can occur by overfilling the tank. Best rule here is when auto shutoff happens at the pump, stop filling. You can also inspect the filler neck for damage and all hose and vacuum lines, for tight fits, cracks, damage or blockages.

Beyond that there are electrical issues and this really requires using the DTC tester while running the engine. Translation, take it in for service.

 

Hi Bob,

Just some info on auto shutoff at the pump. Here in Oregon it is now illegal to put any additional gas into your tank once the auto shutoff has occurred. And since it is also illegal to pump your own gas in Oregon, this has the force of the law as intended.

Jerry Baumchen

 

I've often wondered about the logic of that law in Oregon. (Doesn't New Jersey have the same?) Are the service stations trying to charge more? It would seem that labor costs would make it too expensive for all but the largest stations to survive. I don't really think they can claim any environmental advantage to having an "expert" pumping your gas, can they?

But I have learned a lesson from these threads and that is to not pump more gas in the tank when the shutoff valve goes off!

 

Thanks Bob,
I took it to a mechanic I trust and he suggested replacing the EVAP solenoid (sp) since the valve code came up twice. I have not replaced the gas cap yet, but I guess I should do that at the same time.

Does the solenoid replacement seem reasonable? My mechanic says he is "98.9% certain" that is the problem. If not, he'll look at the canister.

The solenoid costs $65 and he will install it for nothing. Also, are yall aware of the EPA lawsuit against toyota which covers this problem if you have a 1996-1998 vehicle? Kind of funny the problem was still not fixed 4 years later.

 

Wow... I'm not sure how to take that about Oregon law... Nanny government, or full employment. Is it like Back to the Future, ala 1955 Gas station version where 4 of 5 young men encircle your car, pump gas, check the oil, wash off your windscreen??? Or is some more akin to some person who you never want within 20 yards of you, grumbling and muttering under their breath as the pump the gas?

 

Well there's an entire step by step procedure for testing out the components in the repair manual for 441 and 446 trouble codes and they BOTH start at the gas cap. You can certainly inspect the cap yourself to see if its been damage or if age has worn out the sealing gasket.

My point if what if it's not EVAP sensor, but the pressure switch, or just a vacuum line. Is your mechanic going to keep changing out parts until he finds the right one?

 

Hi Bob,

I actually think that the law works quite well; but maybe I am biased.

No, there is usually only one guy who will pump the gas & 'maybe' wash the windshield depending on how busy they are.

Also, Washington state ( just across the river ) has self-serve and their gas is waayy more expensive than here in Oregon.

I would say, 'Come on out & see for yourself.' but we have too many people here already.

Jerry Baumchen

 

You bring up a good point. If it is not the circut/solenoid then we will check all the lines. The gas cap looked okay to me, but I ordered an OEM one for $13.50 shipped, so I guess it can't hurt to go ahead and replace it. I just hope it isn't a canister...I hear those are pricey.

 

That's interesting about the gas prices....but probably tied to differing taxes, rather than self serve versus full service.

I would have thought just opposite for costs, as the Oregon law requires more employees, i.e. labor costs. So it seems Oregon's tax structure is low or Washington State is too high.