I had to do that when I installed my header. But I installed it from the top

 

Yea I have a cat which toned it down some of the rasp. But it is still there once I get on it and get above 3.5K. You couldn't notice it in the clip because I recorded from the driver side. If I had someone drive and was able to be in the back seat I'm sure you could here it in a recording, or even a drive by.

Also I had no issues with installation, but as stated above if installing from underneath there shouldn't be an issue. Well you kinda have to angle it in, but its nothing too difficult.

 

What is the inner diameter of the "downpipe" and the header dimensions

 

2 and 4 are correct for me. nothing major though still doable worth the trouble? YES

 

Will these headers be a problem installing since i have A 3inch cat
Back

 

They should still bolt on as long as you didn't remove the flange that connects to the cat. BUT with a 3 inch NA exhaust , your car will sound like a track car but move like a pacecar

 

lol, so true...i'm saddened by this

 

 

^this is true i would have done my exhaust and a video up for you guys but i decided to get nitto neo gen's tires instead hopefully these tires will improve my 1/4mile times i'll find out wensday.

i also had my new summer dd out of the shop another set back for the ra

 

I have this header and love it. I did add cat to tone down the rasp. It was noticeably quicker, but flow was restricted bit after the cat was added. Using RRM catback.

 

Anyone get a check engine light??? Mine came on after 3 days

 

You most definitely did, you took off your cat with the header install. Some options are available, like ordering this :

http://roadracemotorsports.com/store...products_id=36

Or you can have a high-flow cat welded on at any muffler shop.

 

Was it normal to get it after 3 days??

 

without any sort of cat or O2 spacer then even after 1 day would be normal

 

Yeah i still have my o2 sensors but no cat.... I found it weird that the CEL came on after 3 days.... Shouldnt it have came on right after i removed the cat?? Or maybe an o2 sensor is loose if its possible