regarding your boost and map sensor i cant help you out there. Regarding your ecu/harness: Your ECU is located at the bottom right passenger's side (under the glove box, but inside fenderwall area. to get to it you need to remove about to peices of interior trim. If you car in a 1998, most likeley you have an OBD2a ECU because 1996-1998 ECU's are obd2a and 1999 to 2000 civics are obd2b. On an OBD 2a ecu 2 big plugs are used empty section and then a smaller end plug. On the OBD2b ECU there are 3 plugs in a row. You can tell what kind of ECU you have but reding the middle 3 characters on the top tine of the serials #'s, for example it might be like 12345-P2P-003. the P2P part is going to basically determine your ECU for the most part) there is a link under references spot on this site that helped me out alot. your car, if like ex or hx, i think its ganna be a P2P or P2E. However to run that motor you have efficiently or the pest way is to get a P2T (civic si) Ecu which is obd2b. You plug your existing harness connection into the end of the jumper harness, the jumper harness then connects you to the P2T ecu. Let me know if you want the harness asap after reading this because i put it up on ebay for 100 buy it now. and it probably wont last because everyone sells them for 135(rywire) or 139(boomslang).