Ok, I have a d17a2 and my car randomly (2-3 times/week) idles very roughly. Normally if I cut the engine and start it back up again this problem dissappears for that specific ride. I have checked the air filter (not too dirty). Keep in mind this is a fairly new car with 15,000 miles on it (03 CIVIC EX). Coolant is fine, although at one point I let it run real low and the car *slurrped* when I revved it past 1k into 3k but not after those points. I added more coolant and everything returned to normal. I have 2 JL-Audio 10w0's running on a 400 watt kicker amp, the idling issue does not seem to be affected by the operation of the subs (if i turn them on or off it still idles rough). What is your opinion? What can I do?

 

Its still under warranty, take it to the dealer and let them worry about what to do.
Sounds like a misfire to me. Common for the last few years of OBD-II stuff.

 

But its a brand new car! I have even had the ECU replaced within the last 6 months. Could I fix this problem on my own?

 

Why would you even want to fix it on your own. It is probably something that Honda already knows about or is in the process of fixing. If its under warranty why even bother wasting your time? You paid for the warranty when you bought hte car, you may as well use it.