P0440 Evaporative Emission Control System Malfunction (Not Gas CAP !!!)

[und3rd06]

HI Guys,

I bought a OBDII scanner because I got tired of forking out money for a "scan" every time my Check Engine light came on.

I have been getting a check engine for the past year. 95% of the time it's because of P0440 Evaporative Emission Control System Malfunction. I then unplug my battery. Replug and then I'm good for 75KM before the Check Engine light comes back on.

Now, the mechanics always tell me that it's because of a "loose gas cap" but I can tell you this is FALSE !!!

I erased the P0440 code with my newly acquired OBDII scanner while I had a full tank of gas in my car....and 75 KM later voilà...the Check Engine light came back on.

What else could be the problem ?

Any pointers ?

thanks,

[Marks DTM Calib]

The Evaporative Emission Control consists of a small solenoid valve which is controlled by the ECU. It sits on the back of the 1-3-5 bank cylinder head......two wire connection.

It might simply be that the solenoid valve is egttinga bit iffy or one of teh wires conencting to it is damaged...

The valve simply opens up when cruising to purge the carbon cannister in the right hand wing of petrol fumes.....

[uRabbit]

When that was happening to me, my engine would lock up and I had to get it towed once. Ended up replacing two O2 sensors... Now, my engine light is always on also. But the Cadillac guys said it was cause I need a new Cat-Converter...

[und3rd06]

Ouch,

I read that this OBDII error can be almost everything.

I am new in the domain of mechanics so I don't know what a solenoid lookis like or where it is located (even if you gave me pointer to wher it's located)

ANy chance I can fix this myself ?

thanks

[und3rd06]

one thing is for sure I hope it's not the 02 $en$or$

[1998catera]

when it happened to me, it turned out to be a small air tube that had a small hole worn in it. they didnt see it until they had it torn down for the valve cover gaskets, head gasket, and oil cooler.

they were very gracious and replaced that for free.

isn't cadillac so nice? =] haha...riiiiiight...

[und3rd06]

yeah a free 20$ part after paying for 8 hours of labour I guess.... What a pain...

[1998catera]

However they did give me a 20% discount because I had to do so much in such a short time. All in all, our Cadillac dealer has been extremely fair and pleasant to work with. I have absolutely no complaints.

Oh, the dealer is Shepherd Cadillac in North Manchester, IN.

[und3rd06]

Glad to see you have a good dealer. I guess I should come down there from Canada. My car dealers just look plain suspicious. I don't trust them at all. They always told me gas cap...gas cap... but I know they are full of c$@% because I went on 2 occasions without needing to put gas in my car...so I never did remove the gas cap...

Do you think that the dealership should be able to pinpoint the problem ? Or is it just a hit and miss thing ???

Should I bring it to a dealer or should I give my untrained eye a go...I know jack about cars...every mechanic tells me that Cateras are complex and that comes from the mouth of a Caddy mechanic !!!

[und3rd06]

The thing that really makes me mad is that I bought a OBDII scanner just to fix this problem ....and now I get a "generic" error... That car ... that car... is a love hate relationship for sure...