hey guys any input on a p440 code. code states the problem is in the vacuum lines or the ourge valve i changed the purge valve and the ses light is still on also could not find any vacuum leak anywhere and no jumps or spikes in the idle to say so. anyone ever have this code? Also could it just be stored in the computer b/c it has been on for a few months. also can you still disconnect the battery or do the 20 key revs to deleate codes like the older chevys? or do you need a scan tool? please help. thanks for any input in advance guys.

 

First check your gas cap, make sure its tight. Also here is a little info........https://www.performancetrucks.net/fo...ighlight=p0440

 

Have the PCM reset. It may be a code stored in history.

 

I agree with vortec and flyer...This is a common problem that the dealer will stick it to ya if you don't know how simple a fix it is. Get a new gas cap if the problem persists...I ended up getting a locking GM gas cap and the problem hasn't existed for four months now.

Pat