R0B

I had the same issue with my 2000 Silverado 5.3L and I couldn't get that "secondary air injection" OBD test to clear so I couldn't pass a CA smog check. After doing several cold starts for 2.5 minutes each, I realized the problem. My truck's fuel sender unit is bad and the fuel gauge jumps all over the place when the truck is idling; more often than not, it falls to "empty" and the low fuel light comes on. The system requires there be between 1/2 and 3/4 tank for the OBD to run and I noticed on each cold start, the fuel gauge dropped to empty during the 2.5 min. Not wanting to drop the tank and replace the fuel pump, I decided to just rock the truck side to side for the cold start and continue rocking it for 2.5 min because this prevents the fuel level from dropping. I did this for 4 cold starts just to be sure and IT WORKED!!! All OBD are set and my truck just passed smog. For me, it was important to rock it side to side prior to starting the ignition so the gauge wouldn't start off at empty, then reach in and start the truck and continue rocking it for 2.5 min. Hope this helps someone!