2005 Honda CR-V Owner's Manual - Page 241

Emissions Controls Exhaust Emissions Controls The exhaust emissions controls include three systems: PGM-FI, ignition timing control, and three way catalytic converter. These three systems work together to control the engine's combustion and minimize the amount of HC, CO, and NOx that comes out the tailpipe. The exhaust emissions control systems are separate from the crankcase and evaporative emissions control systems. PGM-FI System The PGM-FI System uses sequential multiport fuel injection. It has three subsystems: air intake, engine control, and fuel control. The powertrain control module (PCM) in automatic transmission vehicles or the engine control module (ECM) in manual transmission vehicles uses various sensors to determine how much air is going into the engine. It then controls how much fuel to inject under all operating conditions. Ignition Timing Control System Replacement Parts The emissions control systems are designed and certified to work together in reducing emissions to levels that comply with the Clean Air Act. To make sure the emissions remain low, you should use only new Honda replacement parts or their equivalent for repairs. Using lower quality parts may increase the emissions from your vehicle. The emissions control systems are covered by warranties separate from the rest of your vehicle. Read your warranty manual for more information. This system constantly adjusts the ignition timing, reducing the amount of HC, CO, and NOx produced. Three Way Catalytic Converter The three way catalytic converter is in the exhaust system. Through chemical reactions, it converts HC, CO, and NOx in the engine's exhaust to carbon dioxide (CO2), nitrogen (N2), and water vapor. 240