If a radio system is installed improperly or if a high-powered type is used, the CIS and other systems may be affected. When the vehicle is to be equipped with a radio, observe the following precautions:
SstMazda 6 Service Manual: Fuel Requirements
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 st ...
Mazda 6 Service Manual: Front/rear abs wheel-speed sensor inspection
Visual Inspection
Remove the wheel and tire, and inspect the sensor for looseness and damage.
Replace the sensor if necessary.
Clearance Inspection
Inspect the clearance between the wheel-speed sensor and the sensor rotor.
Clearance
0.3-1.1 mm {0.012-0.043 in}
Resistance Inspection
...