Rough idle/Loss of Power
 

First off im new to hondas so I dont have a lot of experience with these cars so any kind of help is greatly appreciated. I just bought a 1999 Honda Civic Si with 120000 miles on. The car has exhaust, air intake and a few other things. I had the car running today and it started to almost seem to die out and the rpms really dropped. I take the car for a drive and around 3-4000 RPMS the car seems to lose power and the sound emitted is really different then it hits a certain RPM and everything goes back to normal. I've already changed the spark plugs, distributor cap and rotor. Anyone have any idea what this could be and how I go about fixing it? Thanks

RE: Rough idle/Loss of Power
 

could either be a faulty secondary o2 sensor (http://www.autopartswarehouse.com/de...USOS-4000.html) or your IAVC (http://www.team-integra.net/sections...ArticleID=1174).

go to your local parts place if you have a CEL and check using their scan tool for free.

RE: Rough idle/Loss of Power
 

Attachment 26728

RE: Rough idle/Loss of Power
 

that's funny, b/c i once had a rough idle/loss of power and it threw a cel, and guess what the scanner said it was? a faulty secondary o2 sensor.

RE: Rough idle/Loss of Power
 

Signals from the secondary O2 sensor do not contribute to air/fuel ratios determined by the ECU, so I don't know how to explain your experience. In fact, the sole purpose of this sensor is to verify that the catalytic converter is functioning properly.