Conquering the (NNBS) P0449 Code

[GM Customer Service]

What I want to know, is why you guys don't just get your own usernames! For crying out loud, they are free! You have four or 5 people posting under Louis's account.

Anyway, I just ordered the exact same parts from Amazon today, but I have a P0446 code. Pretty sure it's related. I'll have to check on the broken wire though.

Hello TheFuzz,

You have a very good question. There are 17 of us working as one unit for GM Customer Care to better serve our customers. Yes, there are two of us, Marissa and myself, that you will see most of the time but we do have help from other agents for days when we are out of the office. If you would like to learn more about us, I can direct you to video links that explain what we do.

Sincerely,

Jennifer T.,
GM Customer Care

 

[TheFuzz]

Don't get me wrong, I know most of us (myself included) sincerely appreciate that you guys are on the forums answering questions - it would just make it much easier for us to remember who we are speaking with if you each had your own account, ie "GMCS Jennifer", "GMCS Marissa", "GMCS Laura", etc.

Just a suggestion. Thanks for being here.

 

[Most Hated]

They just repaired the wire.

 

[orange72blazer]

My wife’s 2008 Yukon (5.3 Flex) threw the P0449 code a few weeks ago. I first checked the gas cap condition/tightness and cleared the code with my scanner. Within minutes the code was back and I knew I was in for more than a simple twist ‘o the gas cap fix.

First up was the” Evaporative Emission Canister Purge Solenoid Valve”
AC Delco Part #: 214-1680.
Purchased this from a dealership for $31.00


This installed alongside the driver’s side fuel rail. Once installed, I cleared the code and was good go to……for about a week when the P0449 came creeping back.

Up next was the “revised EVAP canister vent solenoid valve (CVS) assembly and jumper harness.”
AC Delco Part #: 20995472


AC Delco Part #: 19257603


Purchased from Amazon for $40 and $15 respectively.
To access the old CVS, I backed the Yukon up on Rhino Ramps and placed jack stands in place as a precaution. I then lowered and removed the spare tire in order to reach the CVS and associated piping (hard line to EVAP canister and vent hose running up fuel filler hose. Hooked everything up, checked and cleared the code before replacing spare tire.

It’s been about three code free weeks so I’m pretty confident the CVS and jumper took care of it. I used the following as a guide:

TECHNICAL
Bulletin No.: 09-06-04-28C

Thanks, for the info & part #'s. I need to do this also. I tried a new gas cap & cleared out the code but it came right back.

 

[GM Customer Service]

Don't get me wrong, I know most of us (myself included) sincerely appreciate that you guys are on the forums answering questions - it would just make it much easier for us to remember who we are speaking with if you each had your own account, ie "GMCS Jennifer", "GMCS Marissa", "GMCS Laura", etc.

Just a suggestion. Thanks for being here.

Hey there,

Thank you for the compliment. I understand that it may become confusing. I will definitely give your suggestion to my supervisor.

Safe travels,

Jennifer T.,
GM Customer Care

 

[5.3SLT]

Few months, road trips, and thousands of miles later and the fix (1st post) is still sound. G'luck all!

 

[TheFuzz]

Just did this with my truck too, although my CEL was P0446. The CEL has stayed off the last couple of days, but even if it comes back it's good to know that I have the updated part installed. It's a much beefier solenoid and a much bigger filter compared to the original.

Easy job though - took all of 30 minutes, and that was with me taking my time.

 

[Javi]

I have to thank 5.3SLT for this thread. My Yukon Denali 2008 (6.2L AWD) was having a rough idle, and was hard to start after fueling it. It gave me a message saying “Tighten Fuel Cap” and after trying to remote start it gave me a P0496 code.
Until I did all the recommended changes, I wasn’t able to get rid of the Check Engine Light and the rough idle. I highly recommend doing it all at the same time; you lose too much time going after this, one by one like I did.

 

[wired1236]

My wife’s 2008 Yukon (5.3 Flex) threw the P0449 code a few weeks ago. I first checked the gas cap condition/tightness and cleared the code with my scanner. Within minutes the code was back and I knew I was in for more than a simple twist ‘o the gas cap fix.

First up was the” Evaporative Emission Canister Purge Solenoid Valve”
AC Delco Part #: 214-1680.
Purchased this from a dealership for $31.00


This installed alongside the driver’s side fuel rail. Once installed, I cleared the code and was good go to……for about a week when the P0449 came creeping back.

Up next was the “revised EVAP canister vent solenoid valve (CVS) assembly and jumper harness.”
AC Delco Part #: 20995472

AC Delco Part #: 19257603

Purchased from Amazon for $40 and $15 respectively.
To access the old CVS, I backed the Yukon up on Rhino Ramps and placed jack stands in place as a precaution. I then lowered and removed the spare tire in order to reach the CVS and associated piping (hard line to EVAP canister and vent hose running up fuel filler hose. Hooked everything up, checked and cleared the code before replacing spare tire.

It’s been about three code free weeks so I’m pretty confident the CVS and jumper took care of it. I used the following as a guide:

TECHNICAL
Bulletin No.: 09-06-04-28C

Guys

I am having this same exact issue. The dealer first told me a year ago that the gas cap was loose. Cleared the code and sent me on my way. Then in Jan of this year, I get the same P0455 code and they replaced the EVAP soleniod as you first did for $187 parts and labor. Now the eng light is back on and Im sure its the same code. I have not had it checked but Onstar says its an emmision code so Im sure its back.

So I guess I should buy the parts gou list and just replace them myself?

Sent from my GT-P5113 using Tapatalk 2

 

[joshuaryan]

So I replaced my vent solenoid and the corresponding harness along with my gas cap. Engine code went away .....for about a week. Now it comes on sporadically and is currently lit.

I know the technical service bulletin says not to replace the solenoid valve but that's the last remaining part. Any one out there run into this or have their problem fixed by putting on the solenoid valve?