Chapter 4. Exhaust Emissions.|
12594 words. 18 illustrations.
History - why emissions became important. CARB and EPA. Ozone and photochemical smog. Toxic effects. NOx and EGR systems and problems. The other gases of interest - CO, HC, CO2. Man-made global warming? Three-way catalyst. The 1968 Clean Air Act, Senator Muskie's 90% reduction target by 1975.
On Board Diagnostics. OBD1. The need for a common protocol - OBD2. Monitoring, deterioration and fault prediction. EOBD. OBD3 - some difficult implications.
Manufacturer Emission Testing and Certification. US EPA. The CVS process. Chassis dynamometer, inertia load and driving aid. Test procedures and driving cycles. FTP-72. FTP-75. HWFET. SFTP-US06. Certification procedures. Emission data fleet. Emission durability fleet.
Evaporative Emissions. Diurnal, hot soak and running losses. Vapour traps. The SHED (Sealed Housing for Evaporative emissions Determination). Test procedure.
Evaporative Tank Vapour Control. Charcoal canister. Size recommendations. Basic vapour trapping tank breather. Addition of purge valve and Rochester valve. Self-checking. Later systems with leak test capability.
European Emission Testing. ECE 15 test procedure. Total bag samples for HC and CO. ECE 15 + EUDC driving cycle. Switch to CVS process. NEDC (New European Driving Cycle).
Japanese Emission Testing. CVS process. Japanese 10-15 driving cycle. Heat damage tests. Catalyst fire threat. Wooden leg test (pedestrian threat).
Zero Emissions. EPA Tier 1. NLEV. EPA Tier 2. California's TLEV, ULEV, SULEV, ZEV, etc. Table of emissions reduction from 1967 to CA SULEV.
Aftermarket Emission Testing. 'Smog test' not very severe. In USA 14 States choose not have any enforcement. Variation by the county in some States. Basic gas sampling and visual