93 Honda Prelude Si Rough Idle

Hi:

I have a 93 Prelude Si 2.3l engine with some 233,000 mi on it...as of two
weeks ago I got a check engine light that came on and the codes were for
an O2 sensor and a KS sensor. I had the O2 sensor changed (after market
OE) and I haven't had a check engine light come on again but, the car
still runs really rough. I had the plugs changed but, haven't done a cap,
rotor, wire change yet. I'm also confused as to what a knock sensor
actually does. Any advice would be much appreciated.

 

knock sensor detecs early detonation in your engine. could happen if
your ignition timing is off, or you are running incorrect type of gas.
detonation sounds like marbles rattling in a can. it is very bad for an
engine. usually later model hondas have KS installed and automatically
retard the timing if it is detected.