Conquering the (NNBS) P0449 Code

[Smokymance]

Just got my code this weekend on a trip!!!!!!!! 6.2L vehicle.. :-OOOO

 

[Goodinblack]

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?

Updates?

 

[Smokymance]

Updates?

im in the same page on what to replace or not...getting cold here in MICHIGAN...and when you got a CEL my remote start dont work

 

[russellshireman]

A general rule of thumb my shop uses as well as the last shop i worked at to CYOA, was to replace the purge solenoid any time you replace the vent solenoid. They are both mechanical parts with rubber seals, and fuel vapors aren't nice to rubber.

 

[kingbilly68]

I'll be doing this as soon as the rain stops.

 

[Warriorpluto]

Where is this wire under the floor board and what color is it?

 

[swathdiver]

Where is this wire under the floor board and what color is it?

P0449 is for the purge valve which is on the motor and the pink and dark green/white wire run to the ECM under the hood.

 

[HiHoeSilver]

P0449 is for the purge valve which is on the motor and the pink and dark green/white wire run to the ECM under the hood.

I thought 449 was the circuit for the vent valve by the tank.

 

[wjburken]

I thought 449 was the circuit for the vent valve by the tank.

So did I.

 

[swathdiver]

I thought 449 was the circuit for the vent valve by the tank.

So did I.

You're right, I was wrong! Only took you a year to notice! LOL

As Ronaldus Magnus used to tell Gorbachev, "Doveryai, no proveryai"!

 

[CrashTestDummy]

Thanks. 91K.

That damn canister must have a timer on it so when it reaches about 90K miles on the truck, it switches into failure mode.

Same thing happened on my wife's truck, and I followed pretty much the same process you did. No fix until that canister and harness.

 

[rezapci]

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
View attachment 295194

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

Will Thank You for your input
Mine is 08 GMC Yukon 5.3 SLT that I have the same problem but no code! It take me about 10 min to fill up!!!

 

[gbleezy]

Thanks for this thread. My 2008 Tahoe 5.3 Flex with 145k miles threw up the P0449 code and replacing the canister vent valve finally fixed it.