2000 Silverado 1500 4 wheel Drive

I am getting 3 DTC. It has a 5.3L engine and has approximately 152,000 miles. The DTC that I am getting are P0440, P0449, and P0440 again.

I am not sure where to start in the troubleshooting process. Any help will be greatly appreciated. I would like to say thank-you in advanced.

I am getting 3 DTC. It has a 5.3L engine and has approximately 152,000 miles. The DTC that I am getting are P0440, P0449, and P0440 again.

I am not sure where to start in the troubleshooting process. Any help will be greatly appreciated. I would like to say thank-you in advanced.


there is a detailed testing proceedure here that helps locate this issue gas cap codes...

normally it is the vapor cannister is defective/liquid fuel entering it..this is from filling the tank then quickly parking the vehicle..

operation on dusty off roads will plug up the venting solenoid..

the other is the fuel filler tube where you put the nozzle has a hole[rust ] in it...this is then like running with the cap off..

on start up the computer commands fuel vapor testing ,,,it must have the proper vacuum/pressure changes and feedback to pass..if not you get these codes...

Sorry that I have not gotten sooner but been taking care of other cars. But the truck has not been on very dusty roads. Where is the vapor cannister located.

Sorry that I have not gotten sooner but been taking care of other cars. But the truck has not been on very dusty roads. Where is the vapor cannister located.

the fuel tank has mounted on it these vapor controls/ cannister..overfilling the fuel tank then quickly parking , the full tank of fuel , causes this , most of the time...charcoal from the cannister migrates into the controlling valves causing vacuum/pressure in the fuel tank to not be correct..

could also have the fuel tank fill pipe have a rust hole in it ..