Okay so my Xterra tries to turn over but just stalls out I changed the mass airflow sensor ambient air sensor new distributor and cap it gets spark new fuel pump and filter it only throws knock sensor bank 1 code on my reader not sure what is wrong. I was told camshaft sensor or crankshaft sensor. Is it possible that a new timing belt could have gone bad within 9 months?? Thanks in advance for any help you can send my way.

what year and model X ? how many miles. what else was changed when the belt was done ?

were all of the above items changed out at the same time as the belt change, or were they done trying to fix the existing problem?

" tries to turn over but just stalls out " is it sputtering, as if its trying to start, or is it actually starting then stalling out? or does it not fire up at all?

Try to give as much info as you can, as accurate as you can. It will greatly help someone help you out.

If your t-Belt went, you wouldnt be getting it to actually try to start and then stall you would hear it crank, but not try to start.