Daewoo NUBIRA, Owner'S Manual

Page: 196 / 744

1F – 374 I ENGINE CONTROLS
DAEWOO V–121 BL4
EXCESSIVE EXHAUST EMISSIONS OR ODORS
A vehicle fails an emission test. The vehicle has an excessive rotten egg smell.
Important : Excessive odors do not necessarily indicate excessive emissions.
Step Action Value(s) Yes No
1 Were the Important Preliminary Checks performed? Go toStep 2 Go to”Impor-
tant Preliminary
Checks”
2
1. Run the engine until it reaches operating tem-
perature.
2. Perform an emission test.
Does the vehicle pass the emission test?
System OK Go toStep 3
3
1. Connect the scan tool to the Data Link Con-
nector (DLC).
2. Road test the vehicle.
3. Monitor the long term fuel trim memory.
Is the long term fuel trim memory within the value
specified?
115–150
counts
Go toStep 6 Go toStep 4
4 Is the long term fuel trim memory below the value
specified? 115 counts Go to”Diagnos-
tic Aids for
DTC P0172”
Go toStep 5
5 Is the long term fuel trim memory above the value
specified? 150 counts Go to”Diagnos-
tic Aids for
DTC P0171”
6
1. Check for a properly installed fuel cap.
2. Check the fuel system pressure.
3. Perform an injector balance test.
Is the problem found?
Go toStep 7 Go toStep 8
7
1. Repair or replace any fuel system components
as needed.
2. Perform an emission test.
Does the vehicle pass the emission test?
System OK
8
1. Check the ignition system for proper operation.
2. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy de-
posits.
3. Check the ignition wires for cracking, hardness,
or improper connections.
Is the problem found?
Go toStep 9 Go toStep 10