2004 DAEWOO NUBIRA check engine

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.

ENGINE EXHAUST 1G – 9
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
EXHAUST SYSTEM
Notice : When you are inspecting or replacing the exhaust
system components, make sure there is adequate clear-
ance from all points on the underbody to avoid possible
overheating of the floor pan and possible damage to the
passenger compartment insulation and trim materials.
CAUTION : Check the complete exhaust system and
the nearby body areas and the trunk lid for broken,
damaged, missing, or mispositioned parts, open
seams, holes, loose connections, or other deteriora-
tion which could permit hazardous exhaust fumes to
seep into the trunk or the passenger compartment.
Dust or water in the trunk may be an indication of a
problem in one of these areas. Any defects should be
corrected immediately.
MUFFLER
If holes, open seams or any deterioration is discovered
upon inspection of the front muffler and pipe assembly, the
complete assembly should be replaced. The same proce-
dure is applicable to the rear muffler assembly.
Heat shields in the front and the rear muffler assembly
positions, as well as for the catalytic converter and the
connecting pipe, protect the vehicle and the environment
from high temperatures the exhaust system develops.
CATALYTIC CONVERTERS
Notice : The catalytic converter requires the use of un-
leaded fuel only, or damage to the catalyst will result.
The catalytic converters are emission control devices add-
ed to the exhaust system to reduce pollutants from the ex-
haust pipes.
The three–way catalyst has coatings which contain palla-
dium, platinum and rhodium, which simultaneouly lower
the levels of HC, CO and NOx.

2A – 6ISUSPENSION DIAGNOSIS
DAEWOO V–121 BL4
S A high front trim height. This height would increase
the drive axle angle and could cause wobble at
speeds between 24 to 48 km/h (15 to 30 mph).
S Binding or a tight drive axle joint. A tight drive axle
joint or a high front trim height may also cause a
wobble at speeds between 24 to 48 km/h (15 to 30
mph).
S Incorrect, worn, or loose engine mounts causing
adverse drive angles.
Refer to ”General Diagnosis” in this section for actions to
remedy these problems.
Conditions that may produce an effect similar to torque
steer include:
S Incorrect front or rear alignment.
S Frame misalignment or defect.
S Front suspension damage.
S Incorrectly mounted rear crossmember.
TAPERED ROLLER BEARING
Perform the following test to check for looseness in the
hub and bearing assembly on vehicles equipped with rear
disc brakes:
1. Raise and suitably support the vehicle.
2. Remove the rear wheel. Refer to Section 2E, Tires
and Wheels.
3. Remove the brake disc caliper and the brake rotor.
Refer to Section 4E1, Rear Disc Brakes.4. Mount a dial indicator set with a magnetic base to a
control arm or any other stationary part of the ve-
hicle.
5. Push and pull the wheel hub by hand. If the wheel
hub movement exceeds 0.05 mm (0.002 inch), re-
place the wheel bearing. Refer to Section 2D, Rear
Suspension.
6. Install the brake disc caliper and the brake rotor.
Refer to Section 4E1, Rear Disc Brakes.
7. Install the rear wheel. Refer to Section 2E, Tires
and Wheels.
8. Lower the vehicle.

2B – 6IWHEEL ALIGNMENT
DAEWOO V–121 BL4
Whenever a tire is rotated on the wheel, or whenever a tire
or wheel is replaced, rebalance the assembly.
Wheel Runout Diagnosis Chart
StepActionValue(s)YesNo
1Road test the vehicle to verify the vibration com-
plaint.
Are the customer’s concerns verified?–Go to Step 2System OK
21. Perform a vibration diagnosis preliminary
check.
2. Repair any of the problems found.
Is the vibration still present?–Go to Step 3System OK
3Determine at what speed the vibration is present.
Is the vibration over 64 km/h (40 mph)?–Go to Step 4Go to Step 6
4Perform off–vehicle dynamic wheel balance.
Is the vibration still present?–Go to Step 5System OK
5Perform on–vehicle finish balance.
Is the vibration still present?–Go to Step 6System OK
6Perform free lateral and radial on–vehicle runout
check.
Does the runout match the value specified?1.5mm
(0.06 in.)Go to Step 4Go to Step 7
7Perform free lateral and free radial off–vehicle run-
out check.
Does the runout match the value specified?1.3mm
(0.05 in.)Go to Step 8Go to Step 12
81. Index the tire and wheel assembly on the
wheel studs.
2. Obtain the least amount of runout possible.
Does the runout match the value specified?0.76mm
(0.03 in.)Go to Step 9Go to Step 14
9Perform off–vehicle dynamic wheel balance.
Is the vibration still present?–Go to Step 10System OK
10Perform on–vehicle finish balance.
Is the vibration still present?–Go to Step 11System OK
111. Check for any engine driveline imbalance.
2. Thoroughly inspect the drive axles and the
constant velocity joints.
3. Repair any problems found.
Are the repairs complete?–Go to Step 1–
121. Match–mount the tire on the wheel.
2. Perform free lateral and free radial off–vehicle
runout check.
Does the runout match the value specified?1.5mm
(0.06 in.)Go to Step 9Go to Step 13
131. Dismount the tire from the wheel of the sus-
pected assembly.
2. Measure the runout of the wheel.
Does the runout match the value specified?0.8mm
(0.03 in.)Go to Step 15Go to Step 16
14Measure the hub flange runout.
Does the runout match the value specified?0.76mm
(0.03 in.)Go to Step 9Go to Step 17
15Replace the tire.
Is the repair complete?–Go to Step 1–

2B – 10IWHEEL ALIGNMENT
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
FOUR WHEEL ALIGNMENT
The first responsibility of engineering is to design safe
steering and suspension systems. Each component must
be strong enough to withstand and absorb extreme pun-
ishment. Both the steering system and the front and the
rear suspension must function geometrically with the body
mass.
The steering and the suspension systems require that the
front wheels self–return and that the tire rolling effort and
the road friction be held to a negligible force in order to al-
low the customer to direct the vehicle with the least effort
and the most comfort.
A complete wheel alignment check should include mea-
surements of the rear toe and camber.
Four–wheel alignment assures that all four wheels will be
running in precisely the same direction.
When the vehicle is geometrically aligned, fuel economy
and tire life are at their peak, and steering and perfor-
mance are maximized.
TOE
Toe–in is the turning in of the tires, while toe–out is the
turning out of the tires from the geometric centerline or
thrust line. The toe ensures parallel rolling of the wheels.
The toe serves to offset the small deflections of the wheel
support system which occur when the vehicle is rolling for-
ward. The specified toe angle is the setting which achieves
0 degrees of toe when the vehicle is moving.
Incorrect toe–in or toe–out will cause tire wear and re-
duced fuel economy. As the individual steering and sus-
pension components wear from vehicle mileage, addition-
al toe will be needed to compensate for the wear.
Always correct the toe dimension last.
CASTER
Caster is the tilting of the uppermost point of the steering
axis either forward or backward from the vertical when
viewed from the side of the vehicle. A backward tilt is posi-
tive, and a forward tilt is negative. Caster influences direc-
tional control of the steering but does not affect tire wear.
Weak springs or overloading a vehicle will affect caster.
One wheel with more positive caster will pull toward the
center of the car. This condition will cause the car to move
or lean toward the side with the least amount of positive
caster. Caster is measured in degrees and is not adjust-
able.
CAMBER
Camber is the tilting of the top of the tire from the vertical
when viewed from the front of the vehicle. When the tires
tilt outward, the camber is positive. When the tires tilt in-
ward, the camber is negative. The camber angle is mea-
sured in degrees from the vertical. Camber influences
both directional control and tire wear.
If the vehicle has too much positive camber, the outside
shoulder of the tire will wear. If the vehicle has too much
negative camber, the inside shoulder of the tire will wear.
Camber is not adjustable.
STEERING AXIS INCLINATION
Steering Axis Inclination (SAI) is the tilt at the top of the
steering knuckle from the vertical. Measure the SAI angle
from the true vertical to a line through the center of the strut
and the lower ball joint as viewed from the front of the ve-
hicle.
SAI helps the vehicle track straight down the road and as-
sists the wheel back into the straight ahead position. SAI
on front wheel drive vehicles should be negative.
INCLUDED ANGLE
The included angle is the angle measured from the cam-
ber angle to the line through the center of the strut and the
lower ball joint as viewed from the front of the vehicle.
The included angle is calculated in degrees. Most align-
ment racks will not measure the included angle directly. To
determine the included angle, subtract the negative or add
the positive camber readings to the Steering Axis Inclina-
tion (SAI).
SCRUB RADIUS
The scrub radius is the distance between true vertical and
the line through the center of the strut and lower ball joint
to the road surface. Scrub radius is built into the design of
the vehicle. Scrub radius is not adjustable.
SETBACK
The setback is the distance in which one front hub and
bearing assembly may be rearward of the other front hub
and bearing assembly. Setback is primarily caused by a
road hazard or vehicle collision.
TURNING ANGLE
The turning angle is the angle of each front wheel to the
vertical when the vehicle is making a turn.

HYDRAULIC BRAKES 4A – 5
DAEWOO V–121 BL4
DIAGNOSIS
BRAKE SYSTEM TESTING
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake perfor-
mance cannot be made if the roadway is wet, greasy, or
covered with loose dirt whereby all tires do not grip the
road equally. Testing will also be adversely affected if the
roadway is crowned so as to throw the weight so roughly
that the wheels tend to bounce.
Test the brakes at different vehicle speeds with both light
and heavy pedal pressure; however, avoid locking the
brakes and sliding the tires. Locked brakes and sliding
tires do not indicate brake efficiency since heavily braked,
but turning, wheels will stop the vehicle in less distance
than locked brakes. More tire–to–road friction is present
with a heavily–braked, turning tire than with a sliding tire.
Because of the high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
There are three major external conditions that affect brake
performance:
S Tires having unequal contact and grip of the road
will cause unequal braking. Tires must be equally
inflated, and the tread pattern of the right and the
left tires must be approximately equal.
S Unequal loading of the vehicle can affect the brake
performance since the most heavily loaded wheels
require more braking power, and thus more braking
effort, than the others.
S Misalignment of the wheels, particularly conditions
of excessive camber and caster, will cause the
brakes to pull to one side.
To check for brake fluid leaks, hold constant foot pressure
on the pedal with the engine running at idle and the shift
lever in NEUTRAL. If the pedal gradually falls away with
the constant pressure, the hydraulic system may be leak-
ing. Perform a visual check to confirm any suspected
leaks.
Check the master cylinder fluid level. While a slight drop
in the reservoir level results from normal lining wear, an ab-
normally low level indicates a leak in the system. The hy-
draulic system may be leaking either internally or external-
ly. Refer to the procedure below to check the master
cylinder. Also, the system may appear to pass this test
while still having a slight leak. If the fluid level is normal,
check the vacuum booster pushrod length. If an incorrect
pushrod length is found, adjust or replace the rod.
Check the master cylinder using the following procedure:
S Check for a cracked master cylinder casting or
brake fluid leaking around the master cylinder.
Leaks are indicated only if there is at least one drop
of fluid. A damp condition is not abnormal.S Check for a binding pedal linkage and for an incor-
rect pushrod length. If both of these parts are in
satisfactory condition, disassemble the master cyl-
inder and check for an elongated or swollen primary
cylinder or piston seals. If swollen seals are found,
substandard or contaminated brake fluid should be
suspected. If contaminated brake fluid is found, all
the components should be disassembled and
cleaned, and all the rubber components should be
replaced. All of the pipes must also be flushed.
Improper brake fluid, or mineral oil or water in the fluid,
may cause the brake fluid to boil or cause deterioration of
the rubber components. If the primary piston cups in the
master cylinder are swollen, then the rubber parts have
deteriorated. This deterioration may also be evidenced by
swollen wheel cylinder piston seals on the drum brake
wheels.
If deterioration of rubber is evident, disassemble all the hy-
draulic parts and wash the parts with alcohol. Dry these
parts with compressed air before reassembly to keep alco-
hol out of the system. Replace all the rubber parts in the
system, including the hoses. Also, when working on the
brake mechanisms, check for fluid on the linings. If exces-
sive fluid is found, replace the linings.
If the master cylinder piston seals are in satisfactory condi-
tion, check for leaks or excessive heat conditions. If these
conditions are not found, drain the fluid, flush the master
cylinder with brake fluid, refill the master cylinder, and
bleed the system. Refer to ”Manual Bleeding the Brakes”
or”Pressure Bleeding the Brakes” in this section.
BRAKE HOSE INSPECTION
The hydraulic brake hoses should be inspected at least
twice a year. The brake hose assembly should be checked
for road hazard damage, cracks, chafing of the outer cov-
er, and for leaks or blisters. Inspect the hoses for proper
routing and mounting. A brake hose that rubs on a suspen-
sion component will wear and eventually fail. A light and
a mirror may be needed for an adequate inspection. If any
of the above conditions are observed on the brake hose,
adjust or replace the hose as necessary.
WARNING LAMP OPERATION
This brake system uses a BRAKE warning lamp located
in the instrument panel cluster. When the ignition switch
is in the START position, the BRAKE warning lamp should
glow and go OFF when the ignition switch returns to the
RUN position.
The following conditions will activate the BRAKE lamp:
S Parking brake applied. The light should be ON
whenever the parking brake is applied and the igni-
tion switch is ON.
S Low fluid level. A low fluid level in the master cylin-
der will turn the BRAKE lamp ON.
S EBD system is disabled. The light should be ON
when the EBD system is malfunctioning.