check the knock sensor harness as well. If you have a meter you can ohm it to see if it is failing. Or you can spend $1 and go to radio shack and buy a 1megaohm resistor and plug ut into the main efi harness where the knock sensor harness plugs ainto and if it fixes it then the harness or sensor is more than likely your problem. You can buy some nissan knock sensors off of ebay for around $60 plus a new harness for around $24 from one of the site vendors. Search for the knock sensor relocation write up so you don't have to pull the engine or upper and lower intake to replace the old. Hope this helps. Goodluck.