due to high costs for them as well as very little improvement in braking performance over the conventional rear drum-brakes setup. Beginning with all of the Saturn S-series vehicles that were made in late 1999 (sometimes referred to as 1999.5 models) had received improvements to both the SOHC and the DOHC engines in the S series. These changes included revised pistons, new connecting rods, and new crankshaft counterweights in the engine as well. The 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 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 hydrocarbons during the startup of the vehicle, as it would help the oxygen sensors and catalytic converters reach their operating temperatures faster). These vehicles were made to meet the all-new CARB ULEV standards for the 1999 model year. Second generation SC The second generation SC coupes were made from 1997 until 2002. The second generation SC coupes had also moved to the longer wheelbase that the SL sedans and the SW station wagons had used, resulting in an equal wheelbase length across all S-series models. The redesign had resulted in a more curved look for the SC coupes, which gave a slight increase in the vehicle's interior room/space, as well as a completely redesigned exterior of the vehicle itself. For the 1999 model year, a front-opening clamshell door was added to the driver's side of the vehicle. Even though this door on the driver's side of the vehicle had allowed easier access into the vehicle's rear seat, the driver's seat in the vehicle was also able to slide forward to allow easy access to the vehicle's rear seat as well. As a clamshell door, the rear driver's side door could not open unless the front door was open, because the door handle was on the inside of the door itself. Like the first generation SC coupes, the SC1 model lacked a rear sway bar. Third generation Third