Vehicle Emissions: Frequently Asked Questions
DOES MY NEW CAR NEED TO BE TESTED?
New cars are not required to be tested until they
have been registered for five years. Certain vehicles,
like alternative fueled vehicles, have different require-ments.
Find more details at www.myAZcar.com.
WHERE DO I GO TO HAVE MY CAR TESTED?
Emissions testing is available at any of the Phoenix
and Tucson area inspection stations. For locations and
current traffic at a station located near you, click on
WHAT DO I DO IF MY VEHICLE FAILS?
If your vehicle fails the test you must have it
repaired and reinspected. The reinspection is free if
you return within 60 days of your original or subse-quent
paid test with the repair information completed
on the back of the vehicle inspection report.
CAN I HELP MY VEHICLE PASS?
Yes! Vehicles benefit from regular tune-ups, oil and
filter changes, and generally good maintenance. When
going for an emissions test, have the vehicle thor-oughly
warmed up. If it has been serviced (especially
service requiring the battery to be disconnected)
drive the vehicle for a few days to enable the
computer and On-board diagnostic (OBD) monitors
(if your car has them) to reset.
WHAT DOES THE GAS CAP HAVE TO DO
WITH EMISSIONS TESTING?
Most vehicles have a “closed fuel system.” With the
gas cap in place there is moderate pressure in the fuel
tank and lines. This pressure is part of the emissions
control system. If the cap cannot maintain pressure in
the system, the air/fuel mixture can be compromised,
resulting in elevated emissions.
DO ALTERNATIVE FUELED VEHICLES NEED
TO BE TESTED?
All alternative fuel vehicles (except electric, solar
and hydrogen powered) registered in or used to com-mute
into metro Phoenix or Tucson are required to
be emissions-tested before the vehicle can be regis-tered.
New alternative fuel vehicles are subject to an
in-lieu fee until the third registration year. If you have
a new alternative fuel vehicle, you may pay the in-lieu
fee or submit a current emissions test to the Motor
Vehicle Division (MVD).
HOW DO I FIND A GOOD REPAIR FACILITY?
The State of Arizona cannot recommend individual
repair facilities. However, the Vehicle Emissions pro-gram
tracks repair information on vehicles that have
failed the test. You can review the effectiveness of
repair facilities in your area at www.myazcar.com by
clicking the tab “Locate a Repair Facility” on the right.
MY VEHICLE IS DUE FOR INSPECTION, BUT
IT IS OUT OF STATE. WHAT DO I DO?
If your vehicle is out of the State of Arizona for at
least 90 days before it is due for emissions testing, you
may have it tested in the area it is located. If there is
no testing available, you may submit an “Out of State
Exemption.” A service fee applies. See “Exemptions”
WHERE CAN I REPORT A SMOKING VEHICLE?
Both Maricopa and Pima counties operate programs
to notify owners when their vehicles have been
emitting excessive smoke.
In Maricopa County, call (602) 372-2703, or visit
itsWeb site at:
To report a smoking vehicle in Pima County, call (520)
622-5700, or visit:
Publication Number: FS 08-12
I AM NEW TO ARIZONA. WHAT DO I DO TO
REGISTER MY CAR HERE?
If you reside in the emission control areas of Pima
or Maricopa counties, you should have your vehicle
emissions-tested first. Check www.myazcar.com to
see if your car is required to be tested. Then take
your passing test result and your vehicle to any MVD
office to register in Arizona. You can look for an MVD
office at: www.azdot.gov/mvd/index.asp
HOW MUCH DOES AN EMISSIONS TEST COST?
Fees vary by location and vehicle size and type. A
complete schedule of the test fees can be found at
WHAT IS OBD AND HOW DOES IT WORK?
On-board diagnostic systems (OBD) were devel-oped
in the 1980s to help technicians diagnose and
service the computerized engine systems of modern
vehicles. A new generation of these systems is found
on 1996 and newer vehicles. These systems monitor
the same components, use the same computer
“language” and have the same criteria for evaluating
the systems and for indicating the problems to the
driver and the repair technician.
The OBD system provides drivers with an early
warning of malfunctions through a dashboard “Check
Engine” light (also known as a Malfunction Indicator
Light or MIL). This early warning light helps protect
the environment and identifies problems before they
become major repair bills.
WHY DOES OBD TESTING REPLACE
TAILPIPE TESTING ON NEWER VEHICLES?
The OBD II system is required on 1996 and newer
vehicles. While the tailpipe test looks at the vehicle
exhaust to determine if the vehicle is running
efficiently, OBD looks for broken or malfunctioning
components which are causing or will cause emissions
failure if not repaired. OBD often identifies failing
components before tailpipe emissions would fail. This
often allows for repair at a much lower cost than a
malfunctioning component damaging the engine or
HOW DOES THE DRIVER KNOW THERE IS A
When the OBD system determines that a problem
exists, a corresponding “Diagnostic Trouble Code” is
stored in the computer memory. The computer also
illuminates the dashboard “Check Engine” light,
informing the driver that service is needed. If the light
is flashing, the problem is serious and needs immediate
WHERE CAN I GET MORE INFORMATION?
There are two Web sites; www.vei.azdeq.gov and
www.myazcar.com can provide most of the information
you need to find an inspection station, repair facility,
test fees, exemptions and much more.
We have an On-Board Diagnostics (OBD) Test Fact
Sheet similar to this and an OBD informational
brochure that is also available. They can be found on
the ADEQ Web site www.azdeq.gov, click on the
heading “Brochures & Fact Sheets”.
For vehicle specific information, or for information
not covered in the above resources you may contact
Vehicle Emissions Inspection Program staff in Phoenix
at (602) 771-3950 or in Tucson at (520) 745-4536.
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