United States
Environmental Protection
Agency
Office of
Public Affairs (A-107)
Washington DC 20460
&EPA Environmental News
FOR RELEASE: FRIDAY, JUNE 29, 1989
Martha Casey (202) 382-4378
1988 SURVEY
SHOWS CONTINUED
REDUCTIONS IN
MOTOR VEHICLE
TAMPERING
Results of the U.S. Environmental Protection
Agency's 1988 Motor Vehicle Tampering Survey continue
to show significant reductions in catalytic-converter
tampering and fuel switching. The findings are from
communities that include visual checks for these
items in their vehicle-inspection programs.
Many states and localities have adopted vehicle-
inspection programs to comply with certain Clean Air
Act requirements. Local programs include inspection
and maintenance programs (l/M), which test tailpipe
idle emissions, and anti-tampering programs (ATPs)
where the emission-control components are visually
inspected for evidence of tampering and fuel switching.
Tampering among vehicles not covered by either of
these programs was 23 percent, compared to 17 and 16
percent for those vehicles covered by ATP-only or l/M
plus ATP, respectively.
William K. Reilly, EPA Administrator, said, "By
stopping tampering and improving maintenance, state and
local vehicle-inspection programs prevent pollution at
its source. Today's findings show that state and local
programs can reduce tampering. They also show us
where we need to redouble our efforts to improve air
quality. The President's new clean air proposals call
for strengthened inspection and maintenance programs
in cities in serious non-attainment."
The survey found that only one percent of the
catalytic converters were removed from vehicles in
places that inspect for converters, while a seven-
percent removal rate was found in non-inspection
areas. Similarly, inlet-restrictor tampering, which
is one indicator of fuel switching, was only two percent
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in areas that inspect for the inlet, while jLt was eight percent in non-
inspection areas. The catalytic converter, which is ruined by fuel
switching, is the primary pollution-control device on 1975 and newer
vehicles.
There are currently 45 operating ATPs in 25 states covering approxi-
mately 30 percent of the nation's light-duty vehicle fleet. These programs
range from roadside pull-over inspections covering one percent of the
local fleet to annual inspection programs covering the entire local
fleet. Model-year coverage and selection of emission-control devices
for inspection vary depending upon local program regulations. Sites
were selected for the 1988 tampering survey based on the need to evaluate
control-program effectiveness instead of methodically sampling the U.S.
vehicle population. Over half (55 percent) of the vehicles surveyed
were covered by an I/M + ATP or an ATP-only program, even though only 30
percent of the vehicles nationwide are subject to such programs.
When the survey's results are weighted to approximate the national
fleet, the overall tampering rate remains an unacceptably high;. 19 percent.
One-third of the surveyed vehicles displayed some form of malfunction,
possible tampering or definite tampering of emission-control components.
The survey also found that 10 percent of the unleaded vehicles not
covered by an I/M and/or ATP had been misfueled with leaded gasoline at
some time. Fuel switching among vehicles in ATP-only and I/M + ATP
areas was five and four percent, respectively. Motorists who use leaded
gasoline in a vehicle that requires unleaded gasoline actually end up
spending extra money, even though leaded gasoline may be slightly cheaper
at the pump. (Although leaded gas currently costs more to produce than
unleaded gas, it is still priced lower than unleaded at the pumps.) Fuel
switching leads to more frequent repairs and tune-ups and accelerates
engine deterioration.
The most serious, persistent environmental problems associated with
emission-control-device tampering and fuel switching are ozone and carbon
monoxide (CO) emissions. A major element of urban smog, ozone is formed
when volatile organic compounds from gasoline vapors, solvents and other
hydrocarbons (HC) and nitrogen oxides (NOx).react with sunlight and high
temperatures. Ozone can cause various adverse effects on the human
body, such as impaired pulmonary functions, symptomatic effects (such
'as cough, shortness of breath and chest pain) and aggravation of pre-
existing respiratory disease. In addition to these health effects,
ozone has been shown to cause crop-yield reductions and damage to forests
as well as to materials like rubber and dyes. EPA estimates that ambient
ozone levels increased five percent from 1986 to 1987, and preliminary
data for 1988 suggest an additional increase of 14 percent last year.
Over 80 cities nationwide still have not met the national air standard
for ozone. The primary health concerns associated with CO are cardio-
vascular effects, particularly aggravation of angina symptoms, and effects
on the central nervous system. Over 50 cities nationwide still have not
met the national air standard for CO.
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Tampering and misfueling can cause dramatic increases in emissions
of HC, CO and NOx. Motor vehicle emissions^in urban areas account for
nearly 60 percent of the total CO and 40 percent of the airborne lead
emitted into the atmosphere annually. Studies show that removing a
catalytic converter or ruining it by using leaded instead of unleaded
fuel can increase HC emissions about 500 percent and CO emissions about
400 percent per vehicle.
Tampering with specific components of the emission-control system
has been identified as a problem since 1978, when EPA conducted its
first tampering survey. EPA's 1988 survey found that air-pump systems
were the most frequently tampered with components (11 percent). Air-pump
tampering ranged from three percent in New Jersey to 18 percent in Orlando,
Fla. Tampering with the air-pump system can increase HC emissions up to
200 percent and CO emissions up to 800 percent. Even in areas which
inspect underhood emission-control devices some tampering remains undetected.
EPA is working with state and local officials to improve the performance
of the local inspection programs in this regard.
Of interest is the slight but measurable one-percent tamjSfering rate
found with the oxygen sensor and computer-control systems. Oxygen-sensor
tampering can cause dramatic emissions increases—an average increase of *
about 450 percent for HC emissions and 1200 percent for CO emissions.
In the 1988 survey, 60 percent of the vehicles were equipped with oxygen
sensors. As the equipped vehicle fleet ages, tampering with these
relatively new devices may increase.
Since the 1968 model year, emission-control devices have been
installed on light-duty trucks and passenger cars. The 1977 Amendments
to the Clean Air Act made it illegal for any automobile dealer, fleet
operator, or repair or service facility to disconnect or tamper with
emission-control devices. EPA enforcement teams inspect car dealers,
automobile repair facilities, muffler shops and other facilities that
may remove or tamper with emission-control equipment. A maximum civil
penalty of $10,000 per vehicle can be levied against new car dealers and
manufacturers. Commercial repair facilities and fleet operators are
subject to a maximum penalty of $2,500.
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1988 TAMPERING SURVEY SUMMARY
Survey
Locat ion
Number of
Vehicles
Tampering
Rate (%)
Misfueling
Rate (%)
Survey
Type*
Refusal
Rate (%)
Tucson, AZ
424
21
5
C
0
Phoenix, AZ
450
22
5
C
0
Stockton, CA
500
21
11
R
1
Baton Rouge, LA
523
21
7
R
8
Houston, TX
550
17
4
R
2
El Paso, TX
515
20
6
R
1
Albuquerque, NM
500
20
6
R
2
Oklahoma City, OK
505
20
10
R
5
San Antonio, TX
533
26

R
5
Columbia, SC
505
20
8
R
2
New York, NY
406
15
2
R
13
New Jersey, NJ
520
9
1
R, C
1
Birmingham, AL
500
18
6
R
3
Orlando, FL
500
21
8
R
3
Medford, OR
328
12
5
C
0
OVERALL	7,259	19	6-3
*R = roadside pullovers, C = centralized inspection stations

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PREVALENCE OF TAMPERING BY COMPONENT
Component/System
Catalytic Converter
Filler Neck
Restrictor
Air Pump System
Air Pump Belt
Air Pump/Valve
Aspirator*
PCV System
Evaporative
Control System
EGR System
Heated Air Intake
Oxygen Sensor and
Computer System
Tampering
Rate (%)
5
6
11
8
7
2
6
6
7
3
1
* Vehicles with aspirated air systems are not equipped with
other listed air-injection components, nor do conventional
systems include aspirators.

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COMPONENT-SPECIFIC TAMPERING RATES (PERCENT) BY SURVEY LOCATION
Emission Control Component or System
Survey
Catalytic
Inlet
Air Pump
PCV
EGR
Evaporative
Any
Location
Converter
Restrictor
System
System
System
System
Compone
Tucson, AZ
1
3
6
9
9
5
21
Phoenix, AZ
2
5
13
9
10
8
22
Stockton, CA
3
10
10
5
7
5
21
Baton Rouge, LA
7
6
11
8
8
6
21
Houston, TX
4
4
10
5
8
6
17
El Paso, TX
5
5
11
6
7
10
20
Albuquerque, NM
5
6
14
4
10
7
20
Oklahoma City, OK
7
9
8
5
6
6
20
San Antonio, TX
8
10
13
7
8
7
26
Columbia, SC
6
8
12
6
8
7
20
New York, NY
3
2
8
6
5
5
15
New Jersey
1
1
3
3
3
2
9
Birmingham, AL
7
6
16
5
7
5
18
Orlando, FL
8
9
18
6
7
6
21
Medford, OR
0
3
4
2
7
2
12
OVERALL
5
6
11
6
7
6
19
Da
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