Emission Gontrol System
The emission control system includes a Three Way Cata-
lytic Convener (TWC), Exhaust Gas Recirculation (EGR)
system,. Positive Crankcase Ventilation (pCV) system and
Evaporative Emission (EVAP) Control system. The emis-
sion control system is designed to meet federal and state
*: D16Y5 engine
Do not smoke during ihis procedure. Keep
any open flame away from your work area.
1. Start the engine. Hold the engine at 3,000 rpm with
n o l o a d ( i n P a r k o r n e u t r a l ) u n t i l t h e r a d i a t o r f a n
comes on. then let it idle.
Connect a tachometer.
Check and, if necessary, adjust the idle speed (see
page 11-220 - 223).
Warm up and calibrate the CO meter according to the
meter manufacturer's instructions.
Check idle CO with the headlights, heater blower,
rear window defogger, cooling fan, and air condition-
N O T E : ( C a n a d a ) P u l l t h e p a r k i n g b r a k e l e v e r u p .
Start the engine, then check that the headlights are
CO mete. should indicate 0.1% maximum.
NOTE: '98 Dl6Y5 engine - lf the idle speed incress-
es to 8101 50 rpm, this means the EVAp system is
purging the canister. To stop the purging temporari-
ly. raise the engine speed above 1,000 rpm with the
accelerator pedal, then slowly release the pedal.
Three Way Catalytic Converter
The Three Way Catalytic Converter (TWC) is used to
conven hydrocarbons (HC), carbon monoxide (CO), and
oxides of nitrogen (NOx) in the exhaust gas to carbon
dioxide (COr), dinitrogen (N,) and water vapor.
D15Y5, D16\r, engine:
00 D16Y8, 81642 engine: