Editing Vehicle emissions control (section)

==Emission control system design==
It was very important to system designers to meet the emission requirements using a minimum quantity of [[catalyst]] material ([[platinum]] and/or [[palladium]]) due to cost and supply issues.
The General Motors "Emissions Control Systems Project Center" was "to follow the operational plans established by previous (GM) Project Centers. Items unique to the "Emissions Control Systems Project Center" (were):
* No Designers - all design work to be done at home divisions.
* Planning activity which will provide the official timing charts, component costs, allocations, etc.

The ("Emissions Control Systems Project Center") (had) seven tasks to perform, such that an emission system, which passes all existing Federal Emission and Fuel Economy legislation is put into production.

These are to work with the car divisions to:
# Define hardware and system requirements.
# Develop design specifications for all hardware all hardware required.
# Review alternative designs and systems.
# Arrange to test and validate systems, which best suits the needs of all concerned.
# Monitor component design and release.
# Follow progress of divisional certification work.
# Keep management and divisions apprised of progress status.

The system implementation (was to) be phased in over three years. In the 1979 model year. California vehicles with 2.5, 2.8 and 3.5 liter engines will have a CLCC system. In 1980 model year, vehicles sold in California and 3.8 and 4.3 liter engines sold federally will have CLCC, and finally in the 1981 model year all passenger cars will have the system. California light and medium duty trucks may also use the c-4 system.  While 1979 and 1980 systems are very similar, the 1981 system (2nd generation) will differ in that it may include additional engine control systems (i.e., electronic spark timing, idle speed control, etc.)

The Emission Control System under development has been designated C-4.This stands for Computer Controlled Catalytic Converter. The C-4 System encompasses Closed Loop Carburetor Control (CLCC) and Throttle Body Injection (TBI) systems.""<ref name=GMtoday/><ref name="auto"/><ref name="auto1"/>