So my sedan sat for two days then I got in it and started it yesterday morning and had a CEL. I am getting a P0449. I filled up gas on Sunday morning before I parked it. I checked the EVAP purged valve on the intake manifold and it is good. It only has 10k miles but I still checked it. I also checked the wiring under the rear of the car and it is fine.


So before I just start replacing things I am wondering. I know it can be a few different things such as:

-gas cap
-canister vent valve solenoid
-vapor canister



If I clear the CEL it comes back right after I turn the car off then on. This makes me think it is something electronic. I pulled the vent valve solenoid on the vapor canister and it appeared to be fine. Also over the past few months I noticed my MPG has been only 27MPG and I usually get 30MPG (both mixed of around town and highway). I know the gas cap and vent valve solenoid are relatively cheap but I would like to see if anyone else has had this problem.

 

I haven't had the issue on the Balt, but over the years as a mechanic I've seen GM vent solenoids fail left and right. Did you just inspect it, or did you try to actuate it with power?

If you didn't, take it off and use some jumper wires and tap it to the battery and see if it gives a satisfying thunk.

Edit: Forgot to add, if you have access to a scan tool(Snap-on, OTC, etc.) you can actuate it via the pcm and see if you have a good power and ground at the connector.

 

I inspected it and push the center of it to make sure it wasn't seized. The spring loaded part of it moved freely. I unfortunately don't easily have access to a scan tool. I will try to use jumper wires and see if it will make the thunk.

 

Did you figure out what the culprit was? My HHR SS just popped the same code after sitting like you said, I cleared the code and it came back after a short ride.

 

vapor canister on the intake manifold. $15 part

 

10-4, thanks for the update!

 

For those that see this thread. The part is called the evap purge selenoid.

It's a very common failure on these car. I went through one every 18 months.

 

GM part # 12592015

 

Still on original (knock on wood)

 

your LDK didn't come with a new intake mani and accessories?

 

Negative. Reused the LNF manifolds.

 

did you atleast get a new turbo with yours?

 

Lol no on that too.

 

 

get acdelco

 

Still rocking my stock one also but I only have 42k miles on the car.

 

So I had a buddy with a scanner run the code and it was the vent solenoid, the purge was clicking and functioning as it should when we tested it. So I replaced the vent solenoid this past weekend and have driven over 3 full drive cycles and it's not going away. Could it be something else other than the vent solenoid?

 

The code points towards the control circuit itself.

 

How do you go about fixing that then?

 

GM part # 12592015

 

Test for power, ground, continuity check wires...

multimeter is your friend