Vehicles with catalytic converters or oxygen sensors must use ONLY UNLEADED FUEL, which will reduce exhaust emissions and keep spark plug fouling to a minimum.
This vehicle will perform best with fuel listed in the table.

* U.S. federal law requires that octane ratings be posted on gasoline station pumps.
Fuel with a rating lower than 87 octane (91 RON) will negatively affect the emission control system performance and could also cause engine knocking and serious engine damage.
CAUTION
Leaded fuel is harmful to the catalytic converter and oxygen sensors and will lead to deterioration of the emission control system and or failures.
Gasoline blended with oxygenates such as alcohol or ether compounds are generally referred to as oxygenated fuels. The common gasoline blend that can be used with your vehicle is ethanol blended at no more than 10 %. Gasoline containing alcohol, such as ethanol or methanol, may be marketed under the name "Gasohol".
Vehicle damage and drivability problems resulting from the use of the following may not be covered by the warranty.
Emission Control SystemMazda 6 Owners Manual: Electrical troubleshooting tools
Jumper wire
A jumper wire is used to create a temporary circuit. Connect the jumper
wire between the terminals of a circuit to bypass a switch.
Caution
Do not connect a jumper wire from the power source line to a body
ground. This may cause burning or other damage to wiring harnesse ...
Mazda 6 Owners Manual: Variable valve timing actuator inspection
L3
Caution
Variable valve timing actuator can not be disassembled it is a
precision unit.
1. Disconnect the negative battery cable.
2. Remove the plug hole plate.
3. Remove the high-tension lead.
4. Remove the oil control valve connector.
5. Remove the ventilation hose.
6. Remove the ...