02 maxima 6spd , wont start drove it 3 days ago changed spark plugs, valve cover gasket,starter an crank position sensor,

 

Need more of a description. Is it turning over? Partial firing? Codes?

Try replacing the original CPS or reseating the plug. Check wiring.

I'm assuming you tried the usual beating the starter with a breaker bar. Did you put the right plugs in? The 00-01 has significantly shorter plugs, and would cause poor combustion (but would likely start)

Also, your lack of punctuation makes it difficult to understand what happened. Which came first, the problem of not starting or you did the work, and now it won't start?

 

Go back and check your work. Hopefully you used OEM for the plugs and CPS.

 

yes i did the work, its turning over just wont start, cant look for codes because that part isnt working on the car. i got the platium plugs at advance not sure if its the right size(will check)

 

Is the red security led in the clock on while you are trying to start the car?

For the OBD code reader, check fuse # 12 in the fuse block to the left of the steering column. Center row, left end.