Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 111

13D-46
INSPECTION PROCEDURE 22
Too high CO and HC concentration when idling
Abnormal air-fuel ratio is suspected.
MUT-II Self-Diag code
Are diagnosis codes displayed?
Check the ignition timing.
(Refer to GROUP 11A - On-vehicle Service.)
MUT-II Data list
21 Engine coolant temperature sensor. (Refer to P.13D-16.)
MUT-II Data list
13 Intake air temperature sensor (Refer to P.13D-14.)
MUT-II Data list
25 Barometric pressure sensor (Refer to P.13D-20.)
MUT-II Data list
59 Oxygen sensor (rear) (Refer to P.13D-62.)
D Transmission: 2nd gear <M/T>, L range <A/T>
D Driving with throttle widely open
OK: 600 - 1,000 mV
MUT-II Data list
11 Oxygen sensor
OK: 600 - 1,000 mV when racing suddenly.
MUT-II Data list
11 Oxygen sensor
OK: Repeat 0 - 400 mV and 600 - 1,000 mV alternately when
idling.
Check the fuel pressure. (Refer to P.13D-82.)
Check the following items.
D Check the injectors for operation sound.
D Check the injectors for fuel leakage.
D Check the ignition coil, spark plugs, spark plug cables.
D Check the compression pressure.
D Check the positive crankcase ventilation system.
D Check the purge control system.
D Check the EGR control system.
Check the trouble symptom.
Replace the catalytic converter.
MPI -
No
OK
OK
OK
OK
OK
OK
NG
OK
NG
Troubleshooting
Probable cause
D Malfunction of the air-fuel ratio control system
D Deteriorated catalyst
Yes
Refer to P.13D-11, INSPECTION CHART FOR DIAGNOSIS
CODES.
NG
Check that the crank angle sensor is installed properly.
NG
Check the engine coolant temperature sensor system.
(Refer to P.13D-16, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
NG
Check the intake air temperature sensor system. (Refer to P.13D-14,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 13.)
NG
Check the barometric pressure sensor system. (Refer to P.13D-20,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 25.)
NG
Check the oxygen sensor (rear) system. (Refer to P.13D-24, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 59.)
NG
Check the oxygen sensor (front) system. (Refer to P.13D-12, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 11.)
OK
Replace the oxygen sensor.
Check trouble symptom.
NG