Saturn S series Twin Cam cylinder head had now featured a new roller-rocker setup with hydraulic tappets and roller cams replacing the conventional bucket lifter setup of the previous engine in the S series. Also introduced for the 1999 model year S-series vehicles that were sold in California was a different type of an exhaust manifold that housed an upstream catalytic converter (this converter had heated up much faster than the conventional unit, and it had also decreased exhaust emissions faster as well), and it also had provisions for an air-injection reaction system (This had injected fresh air into the exhaust to reduce
Exhaust system attributes, such as an array of heat management properties and superior longevity than any other type of exhaust outlet design. For the average consumer, having trouble with an exhaust outlet system may qualify as 'poorer performance'. A header is a manifold specifically designed for performance. During design, engineers create a manifold without regard to weight or cost but instead for optimal flow of the exhaust gases. This design results in a header that is more efficient at scavenging the exhaust from the cylinders. Headers are generally circular steel tubing with bends and folds calculated to make the paths from each