I will probably be putting a K&N CAI and Magnaflow catback exhaust on my 2004 civic dx at the same time. Will I have to reset the ecu? maybe this isn't sounding right but I checked the threads on the ecu and fuel management site and it doesn't sound like it. But how will I be able to tell? Will it run that crappy that my noob senses will be able to tell? And if I do have to reset it, how do I reset it? I found something about disconnecting the battery but not much else, is that all there is to it and how does it work? I Don't mean to be a pain in the *** but am interested in how it works.

 

no. the ecu can compinsate for slight changes like exhaust and intake flow.

 

some people say when they install there intake the check engine light goes on (this happens not very oftin) but if it does just take off the positive cable on the battery and put it back..it should go off

 

thanks for your info, I'm looking foreward to putting them on

 

I put a K&N FIPK intake on my 99 SI and noticed that it began to run better after being driven for about an hour constantly. I've heard about the ECU reset issues but have also heard that disconnecting the battery doesn't do it. I definitely feel that the ecu "learns" how to better use the air but it takes a while for the "learning" to happen. THe more you drive, the better it gets. I also put DC Sports 4-2-1 headers on and didn't notice any difference with time - for the ECU. The headers made a big difference immediately. Next up: catback exhaust. Any recommendations??

 

you could also take the negitave thingy off the ECU its self and let it sit and put it back on after a minute or two and it will reset itself.