2005 Pathfinder

I haven't seen it but Im trying to help them find the problem. A friend's Pathfinder won't start. First time it quit in the carport driveway while driving - low speed. Then it would not start. It was towed to a mechanic. It started for him right away. The mechanic drove it around , restarted it several times. He couldn't find any problem. Hot day - maybe vapor lock ??

The truck was taken back and driven around next day. He went several places - no problem. Went to lunch then they parked it for about 20 minutes, came out, it wouldn't start. It was towed back to the mechanic. This time the mechanic couldn't start it. The mechanic had it all afternoon friday and all day saturday. Couldn't find the problem.

Told my friend to ask the mechanic what the engine codes were. My guess is fuel pump, fuel filter obvious. Think the mechanic checked those right away so doubt that it. This mechanic has done lots of work for several people and is honest and reliable. Maybe the computer or some sensor screwing up? My friend is going to ask the mechanic about the codes today. But anything else to check besides the obvious?

Friend took it to another mechanic because the first guy said couldn't find it. I wouldn't use him again except that he was honest. It was a fuel pump relay.
Something to check.