Cascade Crew

85 T/A WS6 · Posted: Thu Feb 19, 2004 12:49 pm Post subject: OBD II Code

My Yukon has been showing a P0440, Evaporator Emission Control System Malfunction.

Any idea ?

Dewey316 · Posted: Thu Feb 19, 2004 12:50 pm Post subject:

not an obd2 expert at all, but i would guess it is something to do with the evap purge operation, i would check there.

chevymad · Posted: Thu Feb 19, 2004 6:31 pm Post subject:

That definition is in different terms then i'm familiar with. But i think i know what it is.. OBDII systems use a vacuum pump that pumps the air out of the gas tank. Then since it knows how much fuel is in the tank, it also knows how much empty space, it measures how long the vacuum holds. If there is any leaks it sets a code. Usually when I get that code someone didnt tighten the gas cap right, or filled the tank with the engine running. You have a scan tool to reset the ecm? OBDII wont reset just by disconnecting the battery. You have to have a tool to erase the code.

Hopefully i'm thinking of the right code. My scan tool and manuals describe it differently(and neither match the other either).

85 T/A WS6 · Posted: Thu Feb 19, 2004 6:40 pm Post subject:

You nailed it guys, also if you change grades of gas it will throw this. I can clear it again.

Im also looking for a for a Hypertech Programer, I need to recalibrate the speedo for larger tires and more HP !

I have dumped so much $$ into the truck, my poor lil T/A is crying under its blanky !

The K&N FIPK in addition to the Force II Catack is making me dizzy Smile

ttyl

Don