Carlos A

when i start my car it feels like it's having lots of misfires, i diconected sprakplug wire number 2,3, and 4 one at a time and the engine stumbles like its supposed to but when i disconnect wire number 1 nothing happens i just put brand new sparks plugs in it and put different wires still does the same they told me it was my knock sensor can that be whats causing my problem.

P12

It is probably a bad #1 fuel injector. Same thing happened in my 240SX several years ago. I don't think it is a knock sensor. A knock sensor would not cause disconecting #1 cylinder to do nothing, but #2, 3, and 4 to stumble, like you described.