2004 Acura MDX catalytic converter

This shows the total distance your
vehicle has been driven. It measures
miles in U.S. models and kilometers
in the Canadian models.
It is illegal under U.S. f ederal law and
Canadian provincial regulations to
disconnect, reset, or alter the
odometer with the intent to change
the number of miles or kilometers
indicated.
This shows how much f uel you have.
It may show slightly more or less
than the actual amount. The needle
returns to the bottom after you turn
of f the ignition.
Gauges
Inst rument s and Cont rols
Odometer
Fuel Gauge
66
NOTICE:
TACHOMETERTEMPERATURE
GAUGE
FUEL GAUGE
SPEEDOMETER
TRIP METER RESET
BUTTON
TRIP METER
ODOMETER TRIP METER
SELECT
BUTTON
Avoid driving with an
extremely low f uel level. Running out
of f uel could cause the engine to
misf ire, damaging the catalytic
converter.

Always use the parking brake when
you park your vehicle. Make sure
the parking brake is set f irmly or
your vehicle may roll if it is on an
incline.
Set the parking brake bef ore you put
the transmission in Park. This keeps
the vehicle from moving and putting
pressure on the parking mechanism
in the transmission.Make sure the moonroof and the
windows are closed.
Turn of f the lights.
Place any packages, valuables, etc.
in the cargo area, or take them
with you.
Lock the doors.
Never park over dry leaves, tall
grass, or other f lammable
materials. The hot three way
catalytic converter could cause
these materials to catch on fire.If the vehicle is f acing uphill, turn
the f ront wheels away f rom the
curb.
If the vehicle is f acing downhill,
turn the front wheels toward the
curb.
Make sure the parking brake is
f ully released bef ore driving away.
Driving with the parking brake
partially set can overheat or
damage the rear brakes.
Parking T ips
Parking
Driving179

Thediagramsinthissectiongive
you the dimensions and capacities of
your Acura, and the locations of the
identif ication numbers. It also
includes inf ormation you should
know about your vehicle’s tires and
emissions control systems.................
Identif ication Numbers . 252
................................
Specif ications .254
..........
DOT Tire Quality Grading . 256
Unif orm Tire Quality ..................................
Grading .256
.................................
Treadwear .256
......................................
Traction .256
.............................
Temperature .257
.................................
Tire Labeling .258 .......................
Emissions Controls .259
.....................
The Clean Air Act .259
Crankcase Emissions Control ....................................
System .259
Evaporative Emissions Control ....................................
System .259
Onboard Ref ueling Vapor ................................
Recovery .259
...
Exhaust Emissions Controls . 260
....................
PGM-FI System .260
Ignition Timing Control ................................
System .260
Exhaust Gas Recirculation ...................
(EGR) System . 260
Three Way Catalytic ...........................
Converter .260
....................
Replacement Parts . 260
..
Three Way Catalytic Converter . 261
..............
State Emissions Testing . 262
T echnical Inf ormat ion
T echnical Inf ormation251

The exhaust emissions controls
include f our systems: PGM-FI,
Ignition Timing Control, Exhaust
Gas Recirculation and Three Way
Catalytic Converter. These four
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 f rom the crankcase and
evaporative emissions control
systems.
The PGM-FI System uses sequential
multiport f uel injection.
It has three subsystems: Air Intake,
Engine Control, and Fuel Control.
The Powertrain Control Module
(PCM) uses various sensors to
determine how much air is going
into the engine. It then controls how
much f uel to inject under all
operating conditions.This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
The Exhaust Gas Recirculation
(EGR) system takes some of the
exhaust gas and routes it back into
the intake manif old. Adding exhaust
gas to the air/f uel mixture reduces
the amount of NOx produced when
the f uel is burned.
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 (CO ), dinitrogen
(N ), and water vapor.
The emissions control systems are
covered by warranties separate from
the rest of your vehicle. Read your
warranty manual f or more informa-
tion. The emissions control systems are
designed and certif ied 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
Acura replacement parts or their
equivalent f or repairs. Using lower
qualitypartsmayincreasethe
emissions f rom your vehicle.
2
2
Emissions Cont rols
Exhaust Emissions Controls Replacement Parts
PGM-FI Syst emIgnit ion T iming Cont rol Syst em
Exhaust Gas Recirculat ion (EGR)Syst em
Three Way Catalytic Converter
T echnical Inf ormation260

The three way catalytic converter
contains precious metals that serve
as catalysts, promoting chemical
reactions to convert the exhaust
gasses without af f ecting the metals.
The catalytic converter is ref erred to
as a three-way catalyst, since it acts
on HC, CO, and NOx. A replacement
unit must be an original Acura part
or its equivalent.
The three way catalytic converter
must operate at a high temperature
for the chemical reactions to take
place. It can set on f ire any com-
bustible materials that come near it.
Parkyourvehicleawayfromhigh
grass, dry leaves, or other f lamma-
bles.A defective three way catalytic
converter contributes to air pollution,
and can impair your engine’s per-
f ormance. Follow these guidelines to
protect your vehicle’s three way
catalytic converter.
Always use unleaded gasoline.
Even a small amount of leaded
gasoline can contaminate the
catalyst metals, making the three
way catalytic converter inef f ective. Keep the engine tuned-up.
Have your vehicle diagnosed and
repaired if it is misf iring, back-
f iring, stalling, or otherwise not
running properly.
Three Way Catalytic Converter
T echnical Inf ormation261
THREE WAY CATALYTIC CONVERTER
THREE WAY CATALYTIC CONVERTER

.............................
SRS Indicator .28 ,58
....
START (Ignition Key Position) . 79
.......................
Starting the Engine .171
................
With a Dead Battery . 238
........
Steam Coming f rom Engine . 240
Steering Wheel ..................................
Adjustment .76
.............
Anti-theft Column Lock . 79
...
Stereo Sound System . 110,115,125
....................
Storing Your Vehicle .227
........................................
Sun Visor .100
Supplemental Restraint System ......................................
Servicing .31
.........................
SRS Indicator .28 ,58
...................
System Components . 22
..................................
Synthetic Oil .206
.....................................
Tachometer .66
......
Taillights, Changing Bulbs in . 216
.
Taking Care of the Unexpected . 229
....................................
Tape Player .125
Technical Descriptions ......
DOT Tire Quality Grading . 256
.....
Emissions Control Systems . 259Three Way Catalytic
...............................
Converter .261
.......................
Temperature Gauge .67
...................
Tensioners, Seat Belts . 20
............................
Thef t Protection .129
..
Three Way Catalytic Converter . 261
....................................
Timing Belt .213
....................................
Tire Chains .225
.........
Tire, How to Change a Flat . 231
.................................
Tire Labeling .258
Tire Pressure Monitoring ....................
System (TPMS) .178
Low Tire Pressure ...........................
Indicator .64, 177
.......
Tire Pressure Monitor . 64,178
..................
TPMS Indicator . 64,178
...............................................
Tires .221
..............................
Air Pressure .221
.........................
Checking Wear .222
..........................
Compact Spare .230
......
DOT Tire Quality Grading . 256
......................................
Inf lation .221
..................................
Inspection .222
..............................
Maintenance .223
...................................
Replacing .224
......................................
Rotating .223 ...........................................
Snow .225
............................
Specif ications .255
................................
Tire Chains .225
Towing .....................................
A Trailer .188
................
Emergency Wrecker . 244
....
Equipment and Accessories . 188
.............................
Weight Limit .185
Your Vehicle Behind a ............................
Motorhome .190
.........................
Trailer Loading .185
.................
Trailer Towing Tips . 189
.............
Transf er Assembly Fluid . 211
Transmission ...............
Checking Fluid Level . 210
...........................
Fluid Selection .210
..............
Identif ication Number . 252
.............
Shif ting the Automatic . 172
.....................................
Treadwear .256
.......................................
Trip Meter .67
....................................
Turn Signals .72
...................
Tools, Tire Changing . 231
Index
T
VIII