2002 Altima 2.5 no start

223,000 miles had p0340 code, car ran but no rpm above 1,500. checked crank sensor and replaced, still ran poor replaced the other cam sensor same. Checked both sensors for proper battery voltage and grounding all good. Checked for valve movement while cranking- chain is on. Now after sitting a week the car will not start at all. I’m not sure where to go here. I just had a small code reader what am I missing?

P0340 is a good clue to start with. If you clear the codes what comes back after a crank?

From the literature I believe the camshaft signal circuit design is pull-up. Meaning, with the camshaft disconnected from the harness, the white signal wire should not have voltage on it (please confirm this with the key on). Because the camshaft signal voltage comes from the sensor itself you're going to have to check the signal wire for a signal not only at the sensor but also all the way at the ECM behind the glove box to rule out an open in the wire.

I would backprobe the cam sensor with a voltmeter on this white signal wire while cranking and see if you have a signal or not, assuming power and ground is good. If no signal, check the wire for a short to ground with ohmmeter with the ecm and sensor unplugged. If you have a signal, check it at the ECM.