At a minimum, gasoline should meet ASTM specification D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT).
We recommend against the use of gasolines containing MMT. See Additives for additional information.
Gasoline Octane
California FuelChevrolet Cobalt Service & Repair Manual. Intake Manifold Gasket R&R
1.
Remove the intake manifold cover.
2.
Remove the air cleaner outlet duct.
3.
Disconnect the engine harness electrical
connector (1) from the throttle actuator control (TAC), Fig.
1.
...