EVAP Smoke Test And Smog Check Rules By State

A smoke test is how a repair shop finds where an EVAP leak is located, because the code only says that a leak exists. This page explains what the shop does, what the published price rows say and how state emissions programs treat an EVAP code.

By Enrique Reyes, who works at a family run auto repair and smog check shop in Delano, California. The shop has been open since 1972. Author Source

In The Bay

What A Shop Does

Repair shops run the manufacturer's EVAP test with a scan tool, then use a smoke machine to find where the leak is. Mazda's bulletin on locating EVAP leaks uses a smoke tester.

FCA adds a warning for this procedure. Do not remove the original gas cap during a smoke or leak test, because a test adapter in its place can hide the leak.

Some vehicles carry a leak detection pump of their own. Audi describes a vacuum driven pump controlled by the engine computer, which pressurizes the EVAP system and then watches for pressure loss over a set time.

Price Rows

What The Price Rows Say

Two published rows come close to this service, although neither one is a plain smoke test price.

• RepairPal, dated September 3, 2026. $61 to $90 in labor for emission system diagnosis and testing in general. The page does not mention EVAP or a smoke test.
• YourMechanic, no price date, read November 12, 2026. $169.99 for Ford and Toyota and $184.99 for BMW for a check engine light diagnostic on code P0442, including a $50 credit toward the repair.

So ask for the smoke test price before the work starts.

California

California Smog Check Rules

California runs Smog Check statewide through the Bureau of Automotive Repair. On 1996 and newer vehicles the inspection is an OBD II test that checks readiness, trouble codes and the check engine light command. A vehicle fails for any of these reasons.

• The check engine light is commanded on.
• Any trouble code is stored.
• The light does not come on with the key on and the engine off.
• Too many monitors are incomplete.

So a stored EVAP code fails. The bureau says a vehicle will not pass Smog Check with the check engine light on.

The Readiness Rule Has Two Versions

Gasoline vehicles from 1996 to 1999 may have one incomplete monitor, and on 2000 and newer gasoline vehicles only the EVAP monitor may be incomplete. A new regulation took effect October 1, 2025 that requires all monitors to be set. The bureau's fall 2025 newsletter says the pass and fail criteria stay unchanged while it studies Smog Check data.

Older vehicles get a different inspection. On 1976 to 1995 vehicles, California performs a fuel cap test and a low pressure test of the fuel evaporative system.

Other States

What Other State Programs Say

The state file behind this guide tracks emissions programs across the country, and 3 of those programs have ended. In 19 program rows, an EVAP code that turns on the warning light means the vehicle fails.

• Readiness. Arizona, Connecticut, Illinois, North Carolina, New York, Pennsylvania, Rhode Island, Texas and Virginia allow two monitors not ready on 1996 to 2000 vehicles and one on 2001 and newer.
• Indiana and Maryland single out the EVAP monitor. In Indiana it is the only monitor allowed to be incomplete, and in Maryland either the catalyst or the EVAP monitor may be not ready, but not both.
• Texas tests in 18 counties, and Bexar County was added November 1, 2026.
• Arizona tests in the Phoenix and Tucson areas. Lake Havasu City is in Mohave County, which is outside both.
• North Carolina sent the EPA a plan to remove all 19 of its counties, and the state says the change is not in effect until the EPA approves it.
• Washington, Tennessee and Idaho ended testing. Washington stopped on January 1, 2020, most Tennessee counties stopped on January 14, 2022 and Idaho repealed its requirement effective July 1, 2023.
• Colorado lists nine counties in its FAQ, yet the same FAQ says seven.

After The Repair

Getting The EVAP Monitor Ready

Monitors reset when codes are cleared or the battery is disconnected. The EVAP test then has to run and pass again before the monitor reads ready.

New York says getting monitors ready usually takes two drive cycles with a cool down between them. Manufacturers may skip the EVAP test above 85 percent fuel, and Ford's test needs at least 15 percent. Toyota's key off check runs after the engine has been off five hours, according to MOTOR Magazine.

For the procedure in more depth, evapleak.com shows what happens during an EVAP smoke test.

Need A Leak Found Before A Smog Check?

Call (866) 389-3808 and have your inspection due date ready.