How is computer reset on a 2006 chevy silverado 4.

SOURCE: headlights not working on a 2006 chevy silverado

head light has its own relay check it

SOURCE: 2006 5.3ltr chevy silverado z71 p0455 andp0449

These codes are for the evaporative emission system.The 455 is the vent solenoid.The 455 is a large leak in the evap.system.The vent solenoid I would replace because they go bad and will not work because they are under the vehicle in the rear of the truck.There is a bulletin for these and the vent valve is installed in another spot.The number for the bulletin is 02-06-04-037E.You should also look for a broken or loose hose or pipe that might have came off.Specially if you ran over something.If none found it could just be the vent solenoid stuck in the venting position.Good luck.

SOURCE: 2006 chevy silverado 1500 the trucks fell

take it to the dealer if it's waranteed