Buick LaCrosse May Have Dust Intrusion
This bulletin applies to 2017-2018 Buick LaCrosse vehicles. The SES light may be on. DTC P0446 may be stored.
This code may have been set due to dust intrusion into the EVAP canister through the air inlet pipe.
Clean filters in the air inlet to EVAP, clean the line and replace the canister. The inlet pipe with filter housing is attached to the fuel inlet pipe with zip ties.
Disconnect the air inlet pipe from the EVAP canister. Remove the cover from the air inlet housing. Remove both filters from the air inlet and blow dust out of the filters with compressed air.