# The Virginia Emissions Test, Explained (Arlington & Fairfax County)

> How the Northern Virginia emissions test works, why cars fail, and how to pass, for drivers in Arlington, Fairfax and the DC suburbs.

*Tab Motors Auto Repair | Exxon, 4035 Old Dominion Dr, Arlington, VA 22207 · (703) 243-3080*

If you live in Arlington, Fairfax, Alexandria or most of the inner DC suburbs, your car needs an emissions test every two years to renew its registration. It's separate from the safety inspection, and it trips up a lot of people. Here's how it works.

## Why Northern Virginia has emissions testing

The inner suburbs are part of a federally designated air-quality region, so the Commonwealth requires periodic emissions testing to keep older, dirtier vehicles in check. Most gas vehicles from 1996 and newer are included; brand-new cars (roughly their first four model years) are typically exempt.

## How the test works

For 1996-and-newer vehicles, it's an **OBD test**: a technician plugs into your car's computer and confirms the emissions systems are functioning, that there are no active fault codes, and that the "readiness monitors" have completed their self-checks.

## Why cars fail, and "not ready"

The number-one failure is a **check engine light**. An illuminated light is an automatic fail, full stop. The second most common issue is a **"not ready"** status, usually because the battery was recently disconnected or the car's computer was reset, so the monitors haven't finished. The fix for "not ready" is simply to drive the car through a normal mix of city and highway driving for a few days so the monitors complete.

## The usual culprits behind a check engine light

- Failing oxygen (O2) sensor

- A loose or bad gas cap (an easy EVAP fix)

- Catalytic converter below efficiency

- Engine misfire from worn plugs or coils

The advantage of testing at a full-service shop is simple: if your car fails, we [diagnose the cause](../services/engine-diagnostics.html), repair it, and re-test, all in one place. Call TAB Motors at (703) 243-3080.

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Call (703) 243-3080 or visit TAB Motors | Exxon at 4035 Old Dominion Dr, Arlington, VA 22207.