2004 DAEWOO NUBIRA gas

1F – 630IENGINE CONTROLS
DAEWOO V–121 BL4
COMPREHENSIVE COMPONENT
MONITOR DIAGNOSTIC OPERATION
Comprehensive component monitoring diagnostics are
required to monitor emissions–related input and output
powertrain components.
Input Components
Input components are monitored for circuit continuity and
out–of–range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable, i.e.
Throttle Position (TP) sensor that indicates high throttle
position at low engine loads or Manifold Absolute Pressure
(MAP) voltage. Input components may include, but are not
limited to, the following sensors:
S Vehicle Speed Sensor (VSS).
S Crankshaft Position (CKP) sensor.
S Throttle Position (TP) sensor.
S Engine Coolant Temperature (ECT) sensor.
S Camshaft Position (CMP) sensor.
S Manifold Absolute Pressure (MAP) sensor.
In addition to the circuit continuity and rationality check,
the ECT sensor is monitored for its ability to achieve a
steady state temperature to enable closed loop fuel con-
trol.
Output Components
Output components are diagnosed for proper response to
control module commands. Components where functional
monitoring is not feasible will be monitored for circuit conti-
nuity and out–of–range values if applicable. Output com-
ponents to be monitored include, but are not limited to the
following circuit:
S Idle Air Control (IAC) Motor.
S Control module controlled EVAP Canister Purge
Valve.
S A/C relays.
S Cooling fan relay.
S VSS output.
S MIL control.
Refer to ”Engine Control Module” and Sensors in this sec-
tion.
Passive and Active Diagnostic Tests
A passive test is a diagnostic test which simply monitors
a vehicle system or component. Conversely, an active
test, actually takes some sort of action when performing
diagnostic functions, often in response to a failed passive
test. For example, the Exhaust Gas Recirculation (EGR)
diagnostic active test will force the EGR valve open during
closed throttle deceleration and/or force the EGR valve
closed during a steady state. Either action should result in
a change in manifold pressure.
Intrusive Diagnostic Tests
This is any on–board test run by the Diagnostic Manage-
ment System which may have an effect on vehicle perfor-
mance or emission levels.
Warm–Up Cycle
A warm–up cycle means that engine temperature must
reach aminimum of 160°F (70°C) and rise at least 72°F
(22°C) over the course of a trip.
Freeze Frame
Freeze Frame is an element of the Diagnostic Manage-
ment System which stores various vehicle information at
the moment an emissions–related fault is stored in
memory and when the Malfunction Indicator Lamp (MIL)
is commanded on. These data can help to identify the
cause of a fault.
Failure Records
Failure Records data is an enhancement of the EOBD
Freeze Frame feature. Failure Records store the same ve-
hicle information as does Freeze Frame, but it will store
that information for any fault which is stored in onboard
memory, while Freeze Frame stores information only for
emission–related faults that command the MIL on.
COMMON EOBD TERMS
Diagnostic
When used as a noun, the word diagnostic refers to any
on–board test run by the vehicle’s Diagnostic Manage-
ment System. A diagnostic is simply a test run on a system
or component to determine if the system or component is
operating according to specification. There are many diag-
nostics, shown in the following list:
S Misfire
S Front Heated Oxygen Sensor (HO2S1)
S Rear Heated Oxygen Sensor (HO2S2)
S Exhaust Gas Recirculation (EGR)
S Catalyst monitoring
Enable Criteria
The term ”enable criteria” is engineering language for the
conditions necessary for a given diagnostic test to run.
Each diagnostic has a specific list of conditions which
must be met before the diagnostic will run.
”Enable criteria” is another way of saying ”conditions re-
quired.”
The enable criteria for each diagnostic is listed on the first
page of the Diagnostic Trouble Code (DTC) description
under the heading ”Conditions for Setting the DTC.” En-
able criteria varies with each diagnostic and typically in-
cludes, but is not limited to, the following items:
S Engine speed.
S Vehicle speed
S Engine Coolant Temperature (ECT)
S Manifold Absolute Pressure (MAP)

1G – 2IENGINE EXHAUST
DAEWOO V–121 BL4
COMPONENT LOCATOR
EXHAUST SYSTEM
1. Exhaust Rear Muffler
2. Muffler Gasket
3. Exhaust Front Muffler
4. Muffler Gasket
5. Exhaust Front Pipe (1.8D)
6. Exhaust Front Pipe (1.6D)
7. Catalytic Converter8. Exhaust Pipe Front Gasket
9. Exhaust Front Pipe Gasket
10. Exhaust Manifold
11. Catalytic Converter Protective Shield
12. Front Muffler Protective Shield
13. Rear Muffler Protective Shield

ENGINE EXHAUST 1G – 3
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
CATALYTIC CONVERTER
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the oxygen sensor electrical connector.
3. Remove the exhaust manifold cover with the bolts.
4. Remove the catalytic converter upper flange nuts.
Important : The nuts and the stud may unscrew as a unit
because of the high temperature associated with the ex-
hast manifold, but they can be re–used as such
5. Remove the exhaust front pipe mounting bracket
bolt.
6. Remove the nuts from the exhaust front pipe–to–
catalytic converter flange.
7. Remove the catalytic converter and the gasket.
8. Clean the sealing surfaces on the exhaust front
pipe flange and the exhaust manifold.
9. Check the exhaust front pipe and the exhaust man-
ifold for holes, damage, open seams or other dete-
rioration which could permit exhaust fumes to seep
into the passenger compartment.

1G – 4IENGINE EXHAUST
DAEWOO V–121 BL4
Installation Procedure
1. Install the catalytic converter and the gasket to the
exhaust front pipe flange.
Tighten
Tighten the exhaust front pipe–to–catalytic converter
nuts to 40 NSm (30 lb–ft).
Tighten the exhaust front pipe–to–cylinder block bolt
to 50 NSm (37 lb–ft).
2. Install the catalytic converter to exhaust manifold
nuts and the gasket.
Tighten
Tighten the catalytic converter to exhaust manifold
nuts to 40 NSm (30 lb–ft).
3. Install the exhaust manifold conver bolts.
Tighten
Tighten the exhaust manifold cover bolts to 15 NSm
(11 lb–ft).
4. Connect the oxygen sensor electrical connector.
5. Connect the negative battery cable.
EXHAUST FRONT PIPE
Removal Procedure
1. Remove the crossmember lower bracket with the
bolts.

ENGINE EXHAUST 1G – 5
DAEWOO V–121 BL4
2. Disconnect the oxygen sensor connector.
3. Remove the exhaust front pipe mounting bracket
bolt.
4. Remove the nuts from the exhaust front pipe–to–
catalytic converter flange.
5. Remove the nuts from the exhaust front pipe–to–
exhaust front muffler.
6. Remove the exhaust front pipe and the gasket.
7. Clean the sealing surfaces on the exhaust front
muffler pipe flange and the exhaust front pipe.
8. Check the exhaust front pipe for holes, damage,
open seams or other deterioration which could per-
mit exhaust fumes to seep into the passenger
compartment.
Installation Procedure
1. Install the exhaust front pipe and the gasket.
2. Install the nuts from the exhaust front pipe–to–ex-
hasut front muffler.
Tighten
Tighten the exhaust front pipe–to–exhaust front muf-
fler nets to 30 NSm (22 lb–ft).
3. Install the nuts from the exhaust front pipe–to–cata-
lytic converter flange.
4. Install the exhaust front pipe mounting bracket bolt.
Tighten
Tighten the exhaust front pipe–to–catalytic converter
nuts to 40 NSm (30 lb–ft).
Tighten the exhaust front pipe–to–cylinder block bolt
to 50 NSm (37 lb–ft).
5. Connect the oxygen sensor connector.

1G – 6IENGINE EXHAUST
DAEWOO V–121 BL4
6. Install the crossmember lower bracket bolts to 35
NSm (26 lb–ft).
MUFFLER – FRONT
Removal Procedure
1. Remove the nuts and the gasket from the front
muffler pipe to the exhaust front pipe flange.
2. Disconnect the front muffler from the rubber hang-
er.
3. Remove the nuts and the gasket from the rear muf-
fler pipe flange.
4. Remove the front muffler.
5. Check the exhaust pipe and the front muffler for
holes, damage, open seams, or other deterioration
which could permit exhaust fumes to seep into the
passenger compartment or the trunk.
Installation Procedure
1. Connect the front muffler to the rubber hanger.
2. Attach the front muffler and the gasket to the rear
muffler using the nuts. Secure the front muffler to
the rubber hanger.
Tighten
Tighten the front muffler–to–rear muffler nuts to 30
NSm (22 lb–ft).

ENGINE EXHAUST 1G – 7
DAEWOO V–121 BL4
3. Loosely secure the front muffler assembly to the
connecting pipe flange.
4. Secure the front muffler assembly to the connecting
pipe flange with the nuts.
Tighten
Tighten the front muffler–to–exhaust front pipe nuts to
30 NSm (22 lb–ft).
MUFFLER – REAR
Removal Procedure
1. Remove the nuts and the gasket from the rear muf-
fler pipe flange–to–front muffler pipe flange.
2. Detach the rear muffler assembly from the rubber
hangers on the tail pipe end.
3. Remove the rear muffler assembly.
4. Check the rear muffler and the pipe for holes, dam-
age, open seams, and other deterioration which
could permit exhaust fumes to seep into the pas-
senger compartment or the trunk.
Installation Procedure
1. Secure the rear muffler assembly to the rubber
hangers on the tail pipe end.

1G – 8IENGINE EXHAUST
DAEWOO V–121 BL4
2. Secure the nuts and the gasket from the rear muf-
fler pipe flange–to–front muffler pipe flange.
Tighten
Tighten the front muffler–to–rear muffler nuts to 30
NSm (22 lb–ft).