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. Exhaust Manifold Gasket R&R
1.
Remove the secondary air injection
bolts (2) and nuts (1), Fig. 1.
2.
Remove the secondary air injection
studs (3 and 4), Fig. 2.
3.
Remove the secondary air injection
valve assembly (1), Fig. ...