Toyota Supra 1990 Manual page 172

EC-20
EMISSION CONTROL SYSTEMS - Three-Way Catalyst (TWC) System
THREE-WAY CATALYST (TWC) SYSTEM
7M-GE (Federal and Canada)
7M-GE (California)
7M-GTE
Three-Way Catalyst
(Monol ith ic)
Three-Way Catalyst
(Monol ith ic)
Three-Way Catalyst
(Monolithic)
Three-Way Catalyst
IMonolithirl
Three-Way Catalyst
(Monol ith ic)
EC3427
EC3340
EC2907
To reduce HC, CO and NOx emissions, they are oxidized, reduced and converted to nitrogen (N 2 ), carbon dioxide (C0 2 )
and water (H 2 0) by the catalyst.
Exhaust Port TWC Exhaust Gas
HC, CO, AND NOx
:>
OXIDATION AND
~
CO 2
H 2 O
REDUCTION
..........-
N2