Mazda 6 Service Manual: No.5 engine stalls-after start/at idle

No.4 hard to start/long crank/erratic start/erratic crank

No.6 cranks normally but will not start

Other materials:

Mazda 6 Service Manual: Essential Information
Introduction Be careful not to hurt yourself when inspecting your vehicle, replacing a tire, or doing some kind of maintenance such as car washing. In particular, wear thick work gloves such as cotton gloves when touching areas that are difficult to see while inspecting or working on your vehi ...

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 ...