What would cause a 1995 Nissan Pathfinder to not start sometimes and stall while driving after replacing fuel pump fuel filter distributor cap rotor plugs and wires?

Aside from checking the basics, such as the ground wire connection, vacuum hoses, and all ignition and fuel-related tune-up parts, another possibility is the air flow sensor. A bad sensor can cause hard starting, hesitation, and stalling. This is a relatively common problem on Nissan trucks and Pathfinders.