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Bureau of Air Quality
Car Care = Air Care
Cars and light trucks are a major source of air pollution in Pennsylvania.
Vehicle emissions contribute to health and environmental problems such
warming and haze. All cars
emit some pollution, but poorly maintained cars emit more. Visible smoke
after a brief warm-up period indicates an engine malfunction, but most
engine problems don't produce pollution that you can see. Follow your
owner's manual for the recommended maintenance schedule. Not maintaining
your car or ignoring your dashboard "check engine" light can cost you
in future repair costs as well as pollute the air.
When your vehicle was first made, pollution
control equipment was installed to reduce emissions. Tampering
with the equipment on your car is illegal, can increase emissions
and may cause you to fail vehicle inspections in Pennsylvania.
usually indicates engine malfunctions. Find out what the problem
A "Check Engine Soon"
dashboard light on 1996 and newer vehicles is a sign of emission
trouble. Steady light? Make an appointment to see your mechanic
as soon as you can. Blinking light? Reduce speed and seek
assistance to avoid engine damage.
A properly operating gasoline-powered vehicle does not emit visible
smoke once it's warmed up. Different colors of smoke indicate different
engine problems. A smoking vehicle will usually use more gasoline
than one that is repaired, costing you money. Smoking vehicles can
generate 10 to 15 times more pollution than well-tuned vehicles.
Coolant leaking into combustion
block or cyliner head
leaking into combustion chamber
piston rings, valves or cylinders
Incomplete fuel combustion
choke, fuel injection, or
emission system malfunction
compression due to engine wear
* Source: Texas Commission on Environmental
Quality, "When You Care For Your Car, You Care For The Air",
Since 1975, equipment to reduce emissions has been included on most
vehicles. Federal and state law does not allow individuals to tamper
with this pollution control equipment.
What is "tampering?"
Tampering is when someone removes, disconnects, alters, damages
or in any way renders this equipment ineffective. This would also
include using replacement parts that aren't equivalent to the
original or using parts not originally certified for the vehicle
(for example, dual carburetors to replace a single carburetor).
Why do people tamper?
Some people still believe that tampering with a car's emission
controls will improve the vehicle's performance. Changing the
manufacturer's recommended settings for the engine may actually
reduce fuel efficiency. Today's automakers design cars to meet
the best possible balance between performance, mileage and low
Most vehicles in Pennsylvania will be required to undergo some
sort of check for tampering:
and newer vehicles in 17 counties are required to have on-board
diagnostics tests which by their nature will detect tampering;
and older vehicles in 25 counties with separate emission inspections
are required to have visual checks of the catalytic converter,
exhaust gas recirculation (EGR) valve, positive crankcase ventilation
(PCV) valve, fuel inlet restrictor, air pump and evaporative control
system components. Inspectors will check for their presence, whether
they are properly connected and whether they are the appropriate
type for the vehicle.
similar visual check will be performed as part of the safety inspection
in the 42 other counties without emission inspections.
Classic, collectible and antique vehicles are not required to
have visual inspections in any county.
How does a vehicle owner find out what pollution control
parts were part of the vehicle's original configuration?
We strongly suggest you work with a qualified mechanic. Sometimes
making that determination for older cars can be difficult. Standard
reference manuals, such as Chilton's, can be of assistance, but
professionals may have access to subscription services that are
too expensive for individuals. Vehicle owners can replace missing
pollution control equipment with aftermarket parts or used parts
as long as they are made to work in that vehicle. You do not need
to buy a part made by the manufacturer who made the car. When
buying a used vehicle, ask the seller to demonstrate that all
the pollution control equipment is present.
The engines in today's vehicles are largely controlled by electronics.
An on-board computer controls all of those systems and is capable
of monitoring the vehicle to detect a malfunction or deterioration
that will affect your vehicle's performance, fuel efficiency or
emissions. The computer can detect these problems well before the
driver becomes aware of an effect on driveability. This system is
diagnostics" or OBD.
OBD can detect problems that may not be noticeable upon visual
inspection because any component failures that impact emissions
can be electrical or even chemical in nature. A light with a "check
engine" or "service engine soon" will illuminate, warning the driver
of the problem. The car's computer will store a "trouble code" to
provide a technician with potential repair information.
Vehicles of model year 1996 have OBD systems that are reliable,
standardized and accurate enough to include in state vehicle emission
testing programs. Emission testing programs also check whether all
components, such as bulbs and the software to illuminate "check
engine" lights, are working properly.
OBD Fact Sheet