I have a 2001 Integra GS-R and I need help making a decision on getting a header and a high flow cat (2.5"). Currently the car has a Apexi N1 2.5" exhaust.

I need this header to not throw a CEL due to obdII inspections in North Carolina.

I'm thinking of getting a JDM Spec 98+ ITR header, will this fit on the car? I'm very confused because of all the threads dealing with fitment issues, please help if you can thanks.

 

This has been discussed a million times. Try searching. In a nutshell only a handful of headers are CARB legal, although you may be able to sneak an ITR header if it has a heat shield.

BTW the high flow cat won't be CARB legal.

 

My mistake, it doesn't have to be CARB legal, I just need it to not throw CEL lights so I can get it to pass inspection, I'll try searching again but it seriously confusing trying to guess which parts match.

 

If the only criterion is that it not cause a CEL, you should be OK with any header on the market. None should cause a CEL although all are obviously aftermarket, if that matters during a visual inspection.

For the CEL just make sure you install both O2 sensors correctly on the cat.

There was a really good header throwdown on the all-motor thread recently, and there are some very good inexpensive "knockoff" headers available for <$400. The ITR header also compares well to the knockoffs. Some of these headers will bolt straight on, others will require some custom work to connect to a cat w/ O2 sensors.

https://honda-tech.com/forums/all-motor-naturally-aspirated-44/budget-header-showdown-replica-headers-vs-skunk2-alpha-1-8l-dyno-test-3005484/

 

Thank you so much!

 

A header will not cause a cel

 

The JDM ITR header is a different length therefore it will not work without the right sized catalytic converter and exhaust.

 

And I don't think any of the high flow cats are "one size fits all" so you'll have to do some custom work to install.

 

Some high flow cats, such as the T1R have 2 different sizes to either fit a USDM length header or the JDM ITR / 94-99 GSR

 

what is the cel for? if you have an obd2 car you must use both o2 sensors, that by itself could be part of the problem. many race headers only use the prrimary o2. a high flow cat also could be causing the secondary to throw the code if the cat isn't working worth a **** and causing the secondary o2 to believe your cat is malfunctioning. if you can get a jdm itr header, either 96-97 manifold style or a 98+ 4-1 AND a jdm cat you'll be good to go. simply place your secondary 02 in the temp bung on the jdm cat. can't remember if it's a direct fit or not, may have to weld a new bung for the second o2

 

When I think of a high flow cat, I think of a diagnostic scanner reading "Bank1 Sensor2 malfunction".

 

Hahaha it shouldn't even be called a high flow cat, just a fancy word for test pipe hahaha