Mike's Workshop Manuals
: Service manuals for every vehicle
Home
>>
Buick
>>
2008
>>
Allure Super
>>
Repair and Diagnosis
>>
Engine Performance
>>
System
>>
Engine Control System & Fuel System - 5.3L - DTC P0420 To DTC P3449
>>
DTC P0446
>>
Conditions for Setting the DTC
Conditions for Setting the DTC
The fuel tank vacuum is greater than 12 inches H2O vacuum for 5 seconds.
OR
The FTP is less than -2.5 inches H2O or more than +5 inches for 60 seconds after a cold start.