after replacing the o-ring, i started my car(93 civic si) then heard a single poping sound.

anybody know what that could have been?? should i worry?? i've been driving around a month now since that happened.

 

Sounds to me like a Piece of Trash, (Rust or Dirt), Might have become Dislodged from the Distributor Cap when you removed it and Might have caused a Mis-Fire. Meaning the Spark went to the piece of Trash instead of the Diode that connects to the Spark Plug wire..Thus causing that cylinder to fill with gas and then when the spark did make a connection to much gas in that cylinder and it ignited with a little more force causing a Pop?? Does it still do it or did it just do it once??? If once then don't worry..If it still does take the cap back off and make sure you clean the inside of the cap real good..Just my 2 cents might work??/