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
Pollution prevention located near environmentally sensitive estuaries. These areas are particularly impacted by high levels of diesel exhaust, particulate matter, nitrogen oxides, ozone, and sulfur oxides. The solution for reducing port-related pollution is multi-fold, encompassing attainable alternatives and long-term reduction goals. Examples of simple steps include a restriction on engine idling for ships in the port and the use of cleaner grade diesel fuels. Some more expensive measures can be taken to mitigate the pollution of ships. Replacing older model ships with ships containing new engines allows the ships to meet modern emission standards. Exhaust systems can also be retrofitted in order