sdh - i checked my header no o2 hole on the kamikazi headers. im not sure maybe you have newer ones than i do, but i defiantly do not have one.

 

first let me just point out.... i dont have the rrm header. i have the kamikaze. anyway to answer your question. my CEL light came on right away (installed the header, and drove around for 10 mins.). as i mentioned in another thread, my gas mileage actually got better after installing the header (use to have only an intake, and my gas mileage suffered severly - all that extra air with nowhere to go basically. some people say funky air/fuel mix yadda yadda). so basically yes its just a warning. my cars performance and gas mileage is better than ever. trust me you wont have to worry about anyting. well.... other than the annoying light while driving around at night.

 

i have the rrm headers and test pipe, my headers did NOT cause the CEL to come on at all, about 1 month after in installed the headers, i installed the test pipe and the CEL came on right away, ive just been driving with it lit

 

Black,
Buy a diagnostic cpu like this:
http://cgi.ebay.com/ebaymotors/ws/eB...category=43989
Install your header and if/when the CEL light turns on, connect this bad boy, run a check, it will tell you if its your header, then you can clear your CEL...and if it's not your header it will tell you whats wrong so you are never driving blind. Either way you can clear the CEL w/o removing any bulbs or diconnecting anything.
Hope this helps

 

Still waiting for thoughts on this...

 

I got the aem cai, idled for like 20 min, let sit off for another twenty, started it back up, light turned off after 10 sec's or so, personally I think all you have to do is install it with the negative battery cable unplugged and then drive normal and you shouldn't get a light.

 

no, i already have the CAI installed. i want to know this:

when the header causes the CEL, you need to unplug the battery to reset the CEL. do you need to do the idle for the CAI every time you reset the CEL or no?

 

no..
people maintain that you should idle.. but I'll tell you it makes no difference.. idling the car only means the ECU figures out idel right away.. has nothing to do with anything else. Supposedly we have fully adaptive ECU's so it will adapt essentially like a fuel management system is setup. At certain rpms and certain degrees of load/throttle the system will try to obtain certain pre-determined fuel mixtures by adjusting it's injectors etc. So obviously it never programs those when idling. I always just reset, then drive from the start. Plain and simple.

 

Cool. Now I just need another $319...

 

i ordered my rrm headers and im waiting for it to come, so we wont really know if something is wrong with our cars unless we get a diagnostic tester

 

I've been considering this problem for some time now and after having reviewed the factory service manual, read up on o2 sensors, and asking some questions from a car guy at work I have come up with the following idea.

If you look at the positions of the o2 sensors and the relative costs of them you will note a few things. First is the fact that the o2 sensor in the stock header comes before the 1st catalytic converter. This o2 sensor also costs approximately 2 to 3 times as much as the one just before the 2nd catalytic converter. From this we come two two conclusions. First the sensor in the header is more accurate than the in in the flange of the second cat (this is why it costs more). This means that the ecu will use this sensor for its AFR calculations. Second the only reason the second sensor is present is to tell you if the catalyctic converter in the head is working correctly. From this we have two options when replacing the header.

First either install a bung in the new header or replace the sensor in the cat with the sensor from the old header. In my opinion this is a bad solution because you will still get a CEL from it (one for the cat in the head not working).

Second move the sensor from the old header to the front of the second cat and then install a bung in the exhaust pipe after the cat. Then you put the second sensor in downstream of the cat. This will keep your engine running correctly because it still gets good o2 readings from the first sensor and you won't get a CEL because the two sensors will give different readings indicating a functional cat.

If you have a test pipe, you can't do anything except get a MIL eliminator, but if you keep the cat, or as I am going to do, get a high flow cat you can get good readings for the ecu and get rid of the CEL. I haven't tried this yet, but it should work.

Hope this helps.

 

https://www.evolutionm.net/forums/sh...light=bung+cel

This is what the EVO and Subaru guys are doing... I suggest we try this, as I have not heard anything abou this working or not working on the US N/A lancer.