Purge Valve And Vent Valve, What They Do And What They Cost

The purge valve and the vent valve are the two valves the computer operates to run its leak test, and when either one sticks it can set a leak code. This page explains what each valve does, the symptoms of a bad one and what the published price rows say.

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

Valve One

What The Purge Valve Does

The charcoal canister stores gasoline vapor, and with the engine running the computer opens the purge valve so the engine can pull that vapor in and burn it. The valve has a second job during the leak test, because Ford's test opens it to pull about 8 inches of water vacuum on the sealed system.

On Ford's test, a purge valve stuck closed sets P0455, the large leak code. A valve that leaks or is stuck open sets P1450, which is Ford's code for excessive vacuum.

P0496 points in the same direction. General Motors calls it flow during non purge, and Maserati calls it high purge flow, stuck open. Both descriptions mean vapor is flowing into the engine when the valve should be shut. P0443 is a different kind of code, because it describes an electrical problem in the wiring or coil of the purge valve.

Valve Two

What The Vent Valve Does

Fresh air enters the canister through the canister air filter and the vent valve, and for the leak test Ford closes the vent valve to seal the system.

On Ford's test, a vent valve stuck open sets P0455, and a vent valve stuck closed sets P1450.

Dirt, Water And Spider Nests

Manufacturer bulletins trace many vent valve problems to material that gets in from outside.

• General Motors says the valve draws fresh air through a vent at the filler pipe, and dirt or water there can restrict flow, corrode the valve and make the tank hard to fill. Its bulletin covers 2007 to 2010 full size SUVs and the Avalanche.
• Honda traces stuck closed vent codes to dirt in the canister vent tube.
• Kia traces vent codes on the 2017 and later Sportage to spider nests or other objects in the vent hose, most often at the filler neck.

The vent valve codes are P0446 and P0449, and Ford names P0446 the canister vent solenoid circuit.

Symptoms

Signs Of A Bad Purge Valve

The first symptom is usually a stored code, and manufacturer documents list P0455, P0442, P0496 and Ford's P1450.

Recalls describe more serious symptoms. On some 2012 to 2018 Ford Focus vehicles, a stuck purge valve could stall the engine and deform the plastic tank, which upsets the fuel gauge. Ford covers that in safety recall 18S32. On some 2010 to 2011 Fusion and Milan vehicles, a leaking purge valve could build excessive tank vacuum, and repeated cycles may crack the tank and cause a fuel leak or fuel odor.

Some causes are located next to the valve. General Motors found that oil from the cam cover gasket could stick the purge valve on the 2014 to 2018 Impala 3.6L. FCA found a split purge valve hose on some 2015 Grand Cherokee and Durango models.

Price Rows

What The Purge Valve Price Rows Say

Three sources publish a price for this repair, and their numbers do not agree. Every row below keeps its own source and date.

• RepairPal, dated September 3, 2026, estimates $210 to $251 with parts and labor. That includes $146 to $156 for parts and $65 to $95 for labor, and the estimate excludes taxes, fees and location.
• The Kelley Blue Book service guide shows no date and was read on November 12, 2026. It lists $323 to $380 in total, with no separation between parts and labor.
• A Kelley Blue Book article dated March 13, 2025 lists $326.99 to $384.42, and Kelley Blue Book says these figures come from actual repair orders and exclude independent shops and owner work.
• The CarMD 2026 report, covering 2025 data, puts the average at $172 and ranks the purge valve 6 among check engine repairs.
• The CarMD 2025 report, covering 2024 data, puts the average at $144 and ranks the purge valve 5.
• The CarMD 2023 report, covering 2022 data, puts the average at $137 and ranks the purge valve 6.

For more detail on every source, see the purge valve replacement cost page on evapleak.com.

Price Rows

What The Vent Valve Price Rows Say

YourMechanic lists vent valve estimates for individual vehicles only, with no national average, and its page states no price date. These three rows were read on November 12, 2026.

• The 2011 Dodge Nitro is estimated at $182 in total, with $35.95 for the part and $145.99 for labor.
• The 2008 Chrysler PT Cruiser is estimated at $242 in total, with $95.98 for the part and $145.99 for labor.
• The 2015 Fiat 500 is estimated at $239 in total, with $93.05 for the part and $145.99 for labor.

Labor is the same $145.99 in all three rows, so the part price is what changes the total.

Think A Valve Is Stuck?

Call (866) 389-3808 with the code and the year, make and model.