Does a Faulty Canister Purge Valve Increase Fuel Consumption?
2 Answers
A faulty canister purge valve significantly increases fuel consumption. Here are the relevant details: 1. The canister uses activated carbon's adsorption and filtration principle to collect fuel vapors. When the vehicle starts, the canister purge valve opens, releasing the adsorbed fuel vapors into the intake manifold for re-combustion. 2. If the canister purge valve is faulty (leaking), fuel vapors escape into the cylinders before the engine is started, leading to an overly rich air-fuel mixture. This can cause "flooding," resulting in difficulty starting or weak ignition, which consumes a lot of fuel. 3. Additionally, the overly rich mixture leads to incomplete combustion. The engine ECU detects this and adjusts by leaning out the fuel mixture in the next cycle. However, an overly lean mixture also struggles to burn completely, further increasing fuel consumption.
A faulty carbon canister purge solenoid valve can indeed make the car consume slightly more fuel, as I've personally experienced this issue while driving. Its primary function is to recycle gasoline vapors, normally redirecting those evaporated fumes back into the engine for combustion. If it gets stuck open or malfunctions, the gasoline vapors are wasted, escaping directly through the vent. This means you'll need to refuel more frequently to compensate, so although it's a small component, it can actually increase fuel consumption by a few percentage points. After I got mine repaired, the fuel efficiency returned to normal, reminding me to regularly check if the engine warning light is on—early intervention saves money. Adopting better driving habits, like avoiding sudden acceleration, can also help offset some of the impact.
