1987 MAZDA 626 catalytic converter

4A OUTLINE
FE 8Valve—Unleaded Fuel
Read valve Vacuum switch valve Air cleaner
Slow fuel cut
.. . solenoid valve Air bypass
solenoid^ valve^. Engine control unit
EGR control valve
Solenoid valve (for P/S)*
Solenoid valve (for A/C)*
Catalytic converter
* If equipped
4 A—10
76G04A-010

OUTLINE 4A
Exhaust System
Except FE 8Valve—Unleaded Fuel
Front silencer ATX
Main silencer
FE 8Valve—Unleaded Fuel
Exhaust manifold Catalytic converter
M
Only MTX
Front
Middle silencer
76G04A-011
4A-11

4 A AUTO-RETURN CHOKE SYSTEM
AUTO-RETURN CHOKE SYSTEM
[FE 8VALVE—UNLEADED FUEL, MIDDLE EAST, and F6—GENERAL]
r ~ I
76G04A-066
An auto-return choke is adopted to prevent the catalytic converter from over-heating because of over
use of the choke. This system opens the choke valve by causing the choke knob to return when the
engine coolant temperature is more than 67°C (153°F).
TROUBLESHOOTING
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting Guide. (Refer to pages 4A—16, 21, or 22)
Possible cause
" ^ Page
Symptom
System inspection Choke magnet Water thermo switch
Possible cause
" ^ Page
Symptom 4A—40 4A—41 4A—41
Checking order 1 2 3
76G04A-067
System Inspection
1. Make sure that the engine is cold and turn the ig-
nition switch ON.
2. Pull out the choke knob and check that it is held on.
3. Start the engine and check that the choke knob
returns during warming-up.
76G04A-068
4A—40

EXHAUST SYSTEM 4A
FE 8 VALVE-UNLEADED FUEL
Removal and Inspection
1. Remove in the sequence shown in the figure
2. Install in the reverse order of removal.
Torque Specifications

L

22—28 N-m (2.2—2.9 m-kg, 16—21 ft-lb)
34—49 N-m (3.5—5.0 m-kg, 26—36 ft-lb)
55—60 N-m (5.6—8.2 m-kg, 40—59 ft-lb)
.8—11 Nm .8—1.1 m-kg, 69—95 in-lb)
N-m 3 m-kg, 25—38 ft-lb)
76G04A-189
1. Main silencer
2. Middle pipe
3. Pre-silencer
4. Catalytic converter
5. Bracket
6. Front pipe
Inspection
1. Check the catalytic converter and exhaust pipe for
deterioration or restriction.
2. Check the insulation covers welded onto the cata-
lytic converter for damage.
Note
If the insulation cover is touching the catalytic
converter housing, excessive heat at the floor
will occur.
76G04A-190
4A-97

EXHAUST SYSTEM 4B
EXHAUST SYSTEM
f
76G04B-107
The catalytic converter is used to reduce CO, HC and NOx. The converter contains a compound of
platinum and rhodium. It is a three-way catalyst type with a volume of 1,600 cc (98 cu in).
4B—81

4B EXHAUST SYSTEM
REMOVAL AND INSTALLATION
1. Remove in the sequence shown in the figure.
2. Install in the reverse order of removal.
Torque Specifications
1. Main silencer
2. Middle pipe
3. Pre-silencer
86U04A-159
4. Catalytic converter
5. Bracket
6. Front pipe
INSPECTION
1. Check the catalytic converter and exhaust pipe for
deterioration or restriction.
2. Check the insulation covers welded onto the cata-
lytic converter for damage.
Note
If the insulation cover is touching the catalytic
converter housing, excessive heat at the floor
will occur.
86U04A-160
4B—82

Fuel filter Solenoid valve *1 Solenoid valve *1
(No.2 purge control) (No.1 purge control)
Separator Three way
Injector
,Distributor
Fuel pump
In-take filter
Air flow sensor
Water thermo sensor
Knock sensor
switches
Intake air thermo sensor
— Water thermo switch *1 __ j—Ig. switch (ST) j_J,—lg. switch (ON) -A/C switch 'A/C magnet clutch P/S switch —Head light switch —Rear defroster switch —Cooling fun switch —Blower switch —Neutral and clutch
O) <
{/> H m
g >
o 3D >
^Throttle sensor *1
Air valve
Solenoid valve
(ISC)
EGR control valve *1
EGR modulator valve *1
0 1 CO
a *1...Unleaded fuel only
*2...Leaded fuel only
Oxygen
sensor *1
One-way check valve
Shutter valve actuator Catalytic
converter *1 Solenoid valve (VIC)
O c
m
o

EXHAUST SYSTEM (UNLEADED FUEL) 4C
EXHAUST SYSTEM (UNLEADED FUEL)
Exhaust manifold
Catalytic converter
Main silencer
Middle pipe
76G04C-163
The catalytic converter is used to reduce CO and HC. The converter contains a compound of plati-
num and rhodium. It is a two-way catalyst type with a volume of 2,300 cc (140 cu in).
4C—87