Hi my Nissan Almera cuts out after 20min you then have to what 20min before it will start and then cuts out every 5min. I did replace the fuel pump and tested the relay all ok. please help

Replace the fuel and sender assembly everything is attached to that unit pressure regulator fuel pump and float.
the float is what the fuel level in the tank.

fuel relay ?

This is a fuel problem. Make sure the emergency fuel shut off is not engaged. From there check the fuel pump, fuel relay and the fuel filter. Lastly check fuel pressure.

Here is the video of How To Replace the fuel pump.
https://www.youtube.com/watch?v=TF-JnEzcseU

So many possibilities, but I'd guess a fuel pressure problem. Before starting it next time turn the key to on for a few seconds, then off, then on a few seconds, then start. If it starts better you have a weak fuel pump or the fuel pressure is bleeding off somewhere.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/oscar_403cc49e0f00cda7

Code 345 means the cam sensor on bank two is not sending the correct signal to the engine computer. So no spark.
If you have replaced the sensor, the problem could be the cam or the wiring from the sensor to the computer.

Why would anyone replace those parts?

I guess the car was never tested to find any problems

No more to say

Common sense-- tells you that not all those
parts failed at one time or any at all

check for spark when it cuts off when its not starting spray starting fluid in the intake that with check for a fuel problem

i suggest you look at ignition module mounted under coil pack and also crank sensor.

fuel pump problem?? possibly