P0440 and P0449

[loganbryant]

I have 1999 silverado with a 5.3L. 112K miles. I had recently changed my Vapor Canister Vent Valve with an ac delco one. The CEL went away, and then probably four months later it came back on. I replaced the gas cap with an ac delco one as well. Now it reads p0440 and p0449, I figured the next plan of action was the vapor canister purge valve. Any thoughts?

[txab]

You might give this a read.

 

https://www.gm-trucks.com/forums/topic/104569-the-evap-system/

[chem_man]

First thanks to txab for the link to a great writeup!

 

Now to longanbryant, the P0449 code is telling you there is a problem with the EVAP vent valve.  When you replaced the vent valve, did you install the air filter for it in the area on top of the transmission?

 

Attached are a co ies of 2 TSB describing what I am referring to.  While one of them is for a P0446 code, it is applicable to a P0449 code especially if the EVAP vent valve gets full of dirt/water.

 

Evap TSB.pdf Evap TSB1.pdf

[7milesout]

Not wanting to start a new thread about much the same problem, I'll revive and add to this thread.

 

I had the check engine light come on on my 2003 GMC Sierra SCSB 2WD.  The code that came up is P0449.  I read about this and watched some youtube videos, and decided to replace the Vapor Canister Purge Valve Solenoid.  Which requires a bed tilt on this truck.  The bed tilting was easy enough.  Anywho...

 

The point of this thread is 2 things:  1)  To let others know to look for this -> When I popped the connector off the unit, and when I went reconnect the connector to the new unit, both wires from the connector were dangling.  They had broke off about a half inch away from the connector.  I'm going to hazard a guess these wires were either already broke off, or finished breaking off when I popped loose the connector.  They were very brittle.  So this may be other people's issue who replace this unit but then have the problem come back.   As I recall from reading, the P0449 has maybe a couple meanings, one is that the computer is not receiving the signal it expects.  Well, if the wires are broke off, it certainly won't get the signal it expects.

 

2)  I broke one side of the hose connector fitting, when trying to get the damn thing off the Purge Valve Solenoid.  Can anyone help me find a replacement part?  A part number would suffice.  

 

Thanks!

 

 

7milesout