There are two parts to the '03 smog system. There is a crankcase air inlet tube that runs under the intake manifold and hooks up to an air outlet on the intake tube ahead of the throttle body. A PCV valve is hooked up to a hose plugged into the driver's side valve cover, the other end of which plugs into t vacuum port on the back of the blower.
The other part is an exhaust supply line for the EGR system. The EGR line extends from the exhaust crossover to a vacuum operated valve bolted to the back of the blower.
Some tunes are set up to eliminate the EGR (which only works at part throttle anyway). If you have that, there should be a block off plate bolted to the back of your blower where the EGR valve used to be, or the intake line to the EGR valve should be plugged.
