I have a 2006 HHR that has been showing a P0449 & P0496 error codes. I already took the UBEC apart and checked for wiring problems. Everything looked normal, I checked for bent and loose terminals but did not see any. I pulled the two wire connector at both the canister valve near the fuel tank, and also at the purge valve on the side of the engine. There is 12VDC at both connectors. Is there any other diagnosing I can do? I'm assuming either the gas cap or one of the valves is bad, but I'm not one to just start throwing parts at a car if I can avoid it. Any advice? Also any time I get gas the car will no longer start. It will crank and crank but never fire. If I hold the accelerator to the floor while cranking it will start, but will not idle properly for a minute or so without helping it with the accelerator pedal. Any advice? Thanks

 

If you have to hold the accelerator down while starting, pretty sure that usually mean it's a fuel delivery problem.

There is also this:
https://www.chevyhhr.net/forums/problems-service-repairs-42/check-engine-code-help-26431/

 

Hy:

I am new to this forum. I have a 2010 LS. Check engine light on Code PO449. Have read post by Chevy Mgr about service information 2006. cannot find anything about 2010. Does this information also apply to 2010? I have checked voltage at EVAP canister vent solenoid and have voltage there with key on or off. Is this normal?
I need help.
Thanks

 

Have you inspected the gas cap? How many startup cycles have elapsed since it lit up? Have you tried resetting the code (either with a code tool or by disconnecting the battery for a couple of minutes), if so did the code return.

EVAP Vent Solenoid Control p0449 results from : short to ground, high resistance/open, short to voltage.

Voltage on this system is not easy to use diagnostically, since most of it is computer controlled, you know "magic".

Most likely cause is a bad gas cap seal.

Here is a youtube

 

Krazy Curt here. Yes I have replaced the gas cap. It seems to only happen when the car has less then 1/2 tank of fuel. I have reset the code, it does not return right away. Start cycles very before light comes back on.

 

Well I would like to help. Could you please private message me your name, address, phone number, vehicle identification number, and current mileage?

Jessica L.
Chevrolet Customer Care

 

xxxxxxxxx (Krazy Curt)
xxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxx
63000 miles

 

She said "a PM" now every whacko in the world has access to your address and phone number! Haven't you heard of identity theft?

Maybe you can still edit the post.

 

I agree donbrew. Maybe one of the moderators will see it and delete it.

I try to keep my personal info to myself. BUT, that didn't stop someone from using(stealing) my credit card number last week. Racked up almost 2 grand in purchases by the time the fraud department called me.

 

Could you please resend that information in a private message?

Thank you

Jessica L.
Chevrolet Customer Care