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. Cylinder Head R&R
Removal
1.
Remove air inlet duct and resonator.
2.
Disconnect IAC, TPS and MAP sensor.
3.
Disconnect EVAP and PCV hose.
4.
Disconnect purge solenoid tube and
brake booster hose.
...