To keep fuel systems clean, TOP TIER detergent gasoline is recommended. See Fuel (Gasoline).
If TOP TIER detergent gasoline is not available, one bottle of GM Fuel System Treatment Cleaner added to the fuel tank at every engine oil change, can help. GM Fuel System Treatment Cleaner is the only gasoline additive recommended by General Motors. It is available at your dealer.
Diesel Particulate Filter
The Diesel Particulate Filter (DPF)
system filters soot particles out of
the exhaust gases. The system
includes a self-cleaning function that
runs automatically during driving
without any notification. The filter is
cleaned by periodically burning off
the soot particles at high
temperature. ...