Methods and systems are presented for diagnosing a breach of an evaporative emissions system. The methods and systems include repurposing a resonator as a vacuum reservoir to reduce a pressure of an evaporative emissions system so that it may be determined if there is or is not a breach of the evaporative emissions system.

Methods and systems are provided for reducing evaporative emissions from a vehicle. In one example, the vehicle may include a system for capturing emissions including a plurality of vacuum ports coupled to a vacuum source. The plurality of vacuum ports may be disposed in vehicle components prone to emitting hydrocarbon vapors and activation of the vacuum source draws the vapors from the vehicle components to a fuel canister where the evaporative emissions are stored until the fuel canister is purged.

An engine controller controlling an engine including an occlusion reduction catalyst in an exhaust device includes a fuel injection controller that controls a fuel injection amount of an injector, an EGR controller that controls an EGR device, a sulfur purge determiner that determines whether sulfur purging of the catalyst is to be performed, and a sulfur purge controller that executes sulfur purge control if the sulfur purging is performed. The sulfur purge control involves performing a fuel injection to achieve a rich air-fuel ratio at an inlet of the catalyst and prohibiting the exhaust-gas introduction. The sulfur purge controller executes sulfur-purge standby control when a sulfur-purge standby condition is satisfied, and resumes the sulfur purge control when the condition becomes non-satisfied after starting the sulfur-purge standby control. The sulfur-purge standby control involves performing the fuel injection to nearly achieve a stoichiometric air-fuel ratio and prohibiting the exhaust-gas introduction.

Methods and systems are provided for mitigating hydrocarbon breakthrough from an onboard fuel vapor canister during an engine-off condition. In one example, a method may include actively routing ambient air to an exhaust catalyst to reducing a temperature of the exhaust catalyst.

An evaporative emissions control system configured for use with a vehicle fuel tank includes a purge canister, an accelerometer, first and second vent tubes that terminate at first and second vent openings, a first vent valve, a second vent valve, a vent shut-off assembly and a control module. The accelerometer senses acceleration in an x, y and z axis. The first vent valve is fluidly coupled to the first vent tube. The second vent valve is fluidly coupled to the second vent tube. The vent shutoff assembly selectively opens and closes the first and second valves. The control module estimates a location of liquid fuel based on the sensed acceleration from the accelerometer and determines which vent opening is one of submerged and about to be submerged based on the estimated location of the liquid fuel. The control module closes the vent valve associated with the determined vent opening.

An evaporative fuel processing device includes a canister, a purge path connected to the canister and an intake path that is connected to an internal combustion engine and through which purge gas flows from the canister to the intake path, and a flow control valve provided in the purge path to control the flow rate of the purge gas, wherein: the device further includes a first pressure detection unit that detects a first pressure at a first position between the canister and the flow control vale, and a concentration estimation unit that estimates a purge concentration of the purge gas flowing in the purge path; and the concentration estimation unit determines an increase in the first pressure generated by closing the flow control valve based on the detection value from the first pressure detection unit, and estimates the purge concentration based on the determined increase in the first pressure.

An engine controller controlling an engine including an occlusion reduction catalyst in an exhaust device includes a fuel injection controller that controls a fuel injection amount of an injector, an EGR controller that controls an EGR device, a sulfur purge determiner that determines whether sulfur purging of the catalyst is to be performed, and a sulfur purge controller that executes sulfur purge control if the sulfur purging is performed. The sulfur purge control involves performing a fuel injection to achieve a rich air-fuel ratio at an inlet of the catalyst and prohibiting the exhaust-gas introduction. The sulfur purge controller executes sulfur-purge standby control when a sulfur-purge standby condition is satisfied, and resumes the sulfur purge control when the condition becomes non-satisfied after starting the sulfur-purge standby control. The sulfur-purge standby control involves performing the fuel injection to nearly achieve a stoichiometric air-fuel ratio and prohibiting the exhaust-gas introduction.

A method of compensating fuel for each cylinder of an engine during purging may include, compensating a fuel injection time for each cylinder depending on an amount of intake air for each cylinder, an injection pressure of the injector, and an internal pressure of a combustion chamber of the engine; pressurizing a vaporized gas adsorbed into a canister and injecting the pressurized vaporized gas into the intake pipe by operating an active purge pump; and estimating an amount of vaporized gas reaching each combustion chamber and converting the fuel injection time depending on the estimated amount of vaporized gas.

Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine is in a fuel cut-out mode and fuel vapors are being released to the engine via a fuel vapor storage canister.

A fuel vapor treating apparatus includes a canister, a purge pipe, a purge control valve, and a heating device. The canister is configured to store fuel vapor generated in a fuel tank. The purge pipe is configured to deliver the fuel vapor stored in the canister to an intake passage of an internal combustion engine together with air. The purge control valve is configured to be attached to the purge pipe to be selectively opened and closed in order to adjust a purge flow rate. The purge control valve is also configured to be opened based on a purge request that is made after the internal combustion engine is started. The heating device is configured to heat the purge control valve after the internal combustion engine is started and before the purge request is made.