Ford Mustang (2018 year). Manual — part 34

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Fuel economy may decrease with lower
temperatures.

•

Fuel economy may decrease when
driving short distances.

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You will get better fuel economy when
driving on flat terrain than when driving
on hilly terrain.

EMISSION LAW

WARNING

Do not remove or alter the original
equipment floor covering or
insulation between it and the metal

floor of the vehicle. The floor covering and
insulation protect occupants of the vehicle
from the engine and exhaust system heat
and noise. On vehicles with no original
equipment floor covering insulation, do not
carry passengers in a manner that permits
prolonged skin contact with the metal
floor. Failure to follow these instructions
may result in fire or personal injury.

U.S. federal laws and certain state laws
prohibit removing or rendering inoperative
emission control system components.
Similar federal or provincial laws may
apply in Canada. We do not approve of any
vehicle modification without first
determining applicable laws.

Tampering with emissions
control systems including
related sensors or the Diesel

Exhaust Fluid system can result in reduced
engine power and the illumination of the
service engine soon light.

Tampering With a Noise Control
System

Federal laws prohibit the following acts:
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Removal or rendering inoperative by
any person other than for purposes of
maintenance.

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Repair or replacement of any device or
element of the design incorporated into
a new vehicle for the purpose of noise
control prior to its sale or delivery to
the ultimate purchaser or while it is in
use.

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The use of the vehicle after any person
removes or renders inoperative any
device or element of the design.

The U.S. Environmental Protection Agency
may presume to constitute tampering as
follows:
•

Removal of hood blanket, fender apron
absorbers, fender apron barriers,
underbody noise shields or acoustically
absorptive material.

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Tampering or rendering inoperative the
engine speed governor, to allow engine
speed to exceed manufacturer
specifications.

If the engine does not start, runs rough,
experiences a decrease in engine
performance, experiences excess fuel
consumption or produces excessive
exhaust smoke, check for the following:
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A plugged or disconnected air inlet
system hose.

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A plugged engine air filter element.

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Water in the fuel filter and water
separator.

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A clogged fuel filter.

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Contaminated fuel.

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Air in the fuel system, due to loose
connections.

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An open or pinched sensor hose.

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Incorrect engine oil level.

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Incorrect fuel for climatic conditions.

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Incorrect engine oil viscosity for
climactic conditions.

Note: Some vehicles have a lifetime fuel
filter that is integrated with the fuel tank.
Regular maintenance or replacement is not
needed.

Note: If these checks do not help you
correct the concern, have your vehicle
checked as soon as possible.

Noise Emissions Warranty,
Prohibited Tampering Acts and
Maintenance

On January 1, 1978, Federal regulation
became effective governing the noise
emission on trucks over 10,000 lb
(4,536 kg) Gross Vehicle Weight Rating
(GVWR). The preceding statements
concerning prohibited tampering acts and
maintenance, and the noise warranty
found in the Warranty Guide, are
applicable to complete chassis cabs over
10,000 lb (4,536 kg) GVWR.

CATALYTIC CONVERTER

WARNINGS

Do not park, idle or drive your vehicle
on dry grass or other dry ground
cover. The emission system heats up

the engine compartment and exhaust
system, creating the risk of fire.

The normal operating temperature
of the exhaust system is very high.
Never work around or attempt to

repair any part of the exhaust system until
it has cooled. Use special care when
working around the catalytic converter.
The catalytic converter heats up to a very
high temperature after only a short period
of engine operation and stays hot after the
engine is switched off.

WARNINGS

Exhaust leaks may result in entry of
harmful and potentially lethal fumes
into the passenger compartment. If

you smell exhaust fumes inside your
vehicle, have your vehicle inspected
immediately. Do not drive if you smell
exhaust fumes.

Your vehicle has various emission control
components and a catalytic converter that
enables it to comply with applicable
exhaust emission standards.

To make sure that the catalytic converter
and other emission control components
continue to work properly:
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Do not crank the engine for more than
10 seconds at a time.

•

Do not run the engine with a spark plug
lead disconnected.

•

Do not push-start or tow-start your
vehicle. Use booster cables. See Jump
Starting the Vehicle (page 204).

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Use only the specified fuel listed.

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Do not switch the ignition off when your
vehicle is moving.

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Avoid running out of fuel.

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Have the items listed in scheduled
maintenance information performed
according to the specified schedule.

Note: Resulting component damage may
not be covered by the vehicle Warranty.

The scheduled maintenance items listed
in scheduled maintenance information are
essential to the life and performance of
your vehicle and to its emissions system.

If you use anything other than Ford,
Motorcraft or Ford-authorized parts for
maintenance replacements or for service
of components affecting emission control,
such non-Ford parts should be equivalent
to genuine Ford Motor Company parts in
performance and durability.

Illumination of the service engine soon
indicator, charging system warning light or
the temperature warning light, fluid leaks,
strange odors, smoke or loss of engine
power could indicate that the emission
control system is not working properly.

An improperly operating or damaged
exhaust system may allow exhaust to
enter the vehicle. Have a damaged or
improperly operating exhaust system
inspected and repaired immediately.

Do not make any unauthorized changes to
your vehicle or engine. By law, vehicle
owners and anyone who manufactures,
repairs, services, sells, leases, trades
vehicles, or supervises a fleet of vehicles
are not permitted to intentionally remove
an emission control device or prevent it
from working. Information about your
vehicle’s emission system is on the Vehicle
Emission Control Information Decal
located on or near the engine. This decal
also lists engine displacement.

Please consult your warranty information
for complete details.

On-Board Diagnostics (OBD-II)

Your vehicle has a computer known as the
on-board diagnostics system (OBD-II) that
monitors the engine’s emission control
system. The system protects the
environment by making sure that your
vehicle continues to meet government
emission standards. The OBD-II system
also assists a service technician in properly
servicing your vehicle.

When the service engine soon
indicator illuminates, the OBD-II
system has detected a

malfunction. Temporary malfunctions may
cause the service engine soon indicator to
illuminate. Examples are:

1.

Your vehicle has run out of fuel—the
engine may misfire or run poorly.

2. Poor fuel quality or water in the

fuel—the engine may misfire or run
poorly.

3. The fuel fill inlet may not have closed

properly. See Refueling (page 135).

4. Driving through deep water—the

electrical system may be wet.

You can correct these temporary
malfunctions by filling the fuel tank with
good quality fuel, properly closing the fuel
fill inlet or letting the electrical system dry
out. After three driving cycles without these
or any other temporary malfunctions
present, the service engine soon indicator
should stay off the next time you start the
engine. A driving cycle consists of a cold
engine startup followed by mixed city and
highway driving. No additional vehicle
service is required.

If the service engine soon indicator remains
on, have your vehicle serviced at the first
available opportunity. Although some
malfunctions detected by the OBD-II may
not have symptoms that are apparent,
continued driving with the service engine
soon indicator on can result in increased
emissions, lower fuel economy, reduced
engine and transmission smoothness and
lead to more costly repairs.

Readiness for Inspection and
Maintenance (I/M) Testing

Some state and provincial and local
governments may have
Inspection/Maintenance (I/M) programs
to inspect the emission control equipment
on your vehicle. Failure to pass this
inspection could prevent you from getting
a vehicle registration.

If the service engine soon
indicator is on or the bulb does
not work, your vehicle may need

service. See On-Board Diagnostics.