Timing chain?

Back on this project again to summarize, I have compression, fuel and spark. Seems to want to fire on one or two cylinders while cranking. Rpm registers during crank. Timing chain is visibly good with no slop. Get a code for p0340 camshaft sensor A circuit (bank1 or single sensor). Contemplating changing out sensor, but I thought it should start with camshaft sensor fault. Or could that be just most of the time? Injectors flash with node and ether doesn’t work.