MPI <4G9> -
Troubleshooting
13A-144
INSPECTION PROCEDURE 22
Too high CO and HC concentration when idling
Probable cause
Abnormal air-fuel ratio is suspected.
D
Malfunction of the air-fuel ratio control system
D
Deteriorated catalyst
NG
Replace the catalytic converter.
Check the trouble symptom.
OK
NG
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.
NG
Check the fuel pressure. (Refer to P.13A-78*.)
Check the trouble symptom.
OK
Replace the oxygen sensor.
OK
MUT-
II
Data list
11 Oxygen sensor
OK:
Repeat 0 - 400 mV and 600 - 1,000 mV alternately when
idling.
NG
Check the oxygen sensor (front) system. (Refer to P.13A-103, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0130.)
OK
MUT-
II
Data list
11 Oxygen sensor
OK:
600 - 1,000 mV when racing suddenly.
NG
Check the oxygen sensor (rear) system. (Refer to P.13A-106, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0136.)
OK
MUT-
II
Data list
59 Oxygen sensor (rear)
D
Transmission: 2nd gear <M/T>, L range <A/T>
D
Driving with throttle widely open
OK:
600 - 1,000 mV
NG
Check the barometric pressure sensor system. (Refer to P.13A-94,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0105.)
OK
MUT-
II
Data list
25 Barometric pressure sensor (Refer to P.13A-155.)
NG
Check the intake air temperature sensor system. (Refer to P.13A-96,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0110.)
OK
MUT-
II
Data list
13 Intake air temperature sensor (Refer to P.13A-153.)
NG
Check the engine coolant temperature sensor system.
(Refer to P.13A-98, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE P0115.)
OK
MUT-
II
Data list
21 Engine coolant temperature sensor. (Refer to P.13A-154.)
NG
Check that the crank angle sensor is installed properly.
No
Check the ignition timing.
(Refer to GROUP 11A - On-vehicle Service.)
MUT-
II
Self-Diag code
Are diagnosis codes displayed?
Yes
Refer to P.13A-90, INSPECTION CHART FOR DIAGNOSIS
CODES.
NOTE:
*: Refer to the ’96 COLT/LANCER Workshop Manual (Pub. No. PWME9511).