J2J_ATX

Hello all,

I have a 2003 Suburban Z71 and the check engine light has come on. The DTC Codes are:

P0443 - EVAP Control System Purge Control Valve Circuit Malfunction
P0446 - EVAP Control System Vent Control Circuit Malfunction
P0455 - EVAP Control System Leak Detected (gross leak)

I have had the gas cap tested and it tested fine. Also, I just went to put gas in the car and when removing the gas cap you could tell the it was under major air pressure as the tank let out a long windy hiss...

Can anyone advise on where to start with this? Is this something that can be resolved through my own labor and a trip to Autozone? or is this something I should definitely have my dealership resolve?

Thanks for your time!

in2pro

I would start with inspecting the evap lines for any that are pulled loose, cut or broken.
Check the evap canister which I believe is located under the truck on the 03s its a black box looking thing should be fairly close to the gas tank, look for cracks or missing hoses.

Then I would check the connections to the evap control valve.

If you use fuel that is high in alcohol it can be hard on the rubber lines over time..

The "gross leak" should mean something is wide open and you should be able to smell gasoline vapors if not, I would suspect the control valve is defective

J2J_ATX

In2pro,

Thank you for your quick response. I have found instructions on how to replace the EVAP Vent Solenoid. Can you confirm if this is the correct part?

http://www.autozone.com/autozone/cat...&parentId=60-0

Thanks!

in2pro

J2J_ATX,
I unfortunately can't confirm it, I have not had to replace one, I have only had the good fortune to be underneath similar vehicles replacing fuel pumps and in general inspecting the system as a whole...

what I have learned is that in general with GM trucks and SUV's you can count on replacing, fuel pumps, front rotors, alternators, battery and transmissions....