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: Heated oxygen sensor (ho2s) inspection
HO2S Voltage Inspection Note Perform the following inspection only when directed. 1. Warm up the engine and run it at idle. 2. Disconnect the HO2S connector. 3. Connect the voltmeter test leads to the following HO2S terminals: HO2S (front and rear) - (+) leadterminal A - (-) le ...

Mazda 6 Service Manual: Oil pressure switch inspection
Caution Water or foreign objects entering the connector can cause poor connection or corrosion. Be sure not to drop water or foreign objects on the connector when disconnecting it. On-vehicle Inspection (harness inspection) 1. Disconnect the negative battery cable. 2. Remove the under ...