Mazda 6 Service Manual: No.4 hard to start/long crank/erratic start/erratic crank

No.3 will not crank

No.5 engine stalls-after start/at idle

Other materials:

Mazda 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: On-board diagnostic test
DTCs Reading Procedure 1. Perform the necessary vehicle preparation and visual inspection. 2. Connect WDS or equivalent to the vehicle DLC-2 16-pin connector located as shown in the figure. 3. Retrieve DTCs by WDS or equivalent. Pending Trouble Code Access Procedure 1. Perform the necessary ...