It has 4 of them.
That year has 2 oxygen sensors.
It has 1
There are 2 knock sensors on these motors. They are located in the valley cover under the intake manifold.
ONE.
It has 2 and both of them are underneith the intake manifold.
That year used ONLY 2 sensors and there up close to the engine in the exhaust system/pipes.
It has 4 and there all screwed into the exhaust system.
4 and there all screwed into the exhaust system/pipes.
The 6.0L has 2 knock sensors and there both underneith the intake manifold. You can not see are get to them until you remove the intake.
26 gallons
There are 4 of them. 2 Up streams and 2 down streams.
You can purchase a used 2003 Chevy Silverado from many different places. You can check Ebay or Yahoo Auto. You can also look in your local Chevrolet dealership for used vehicles.