[tempfixit]

DO NOT replace the knock sensor, they rarely fail. (Save your money on knock sensor) The code is set because something is causing a vibration to set the code. Deal with the original issue and code should clear.

Do you have to step on the accelerator to start it???

Try checking and cleaning the IAC/FIC and port opening for carbon build up (they are not easy to get to but doable)

Also take off the cap and rotor again and also remove plate to check the optical sensor for any grayish/brown dust on it. If dust is present this is a indication that the distributor shaft bearing is getting bad and the distributor will need to be replaced.

Have you checked the fuel pressure???

Also check the Throttle Position Sensor.

You could also try disconnecting the oxygen sensor to see if that helps any.

There is a thread I believe titled Factory Online Service manual, check it out I believe it will be a lot of help to you.