View Single Post
Old 07-20-2013, 01:41 AM   #2
Teryn It Up
Scooby Newbie
 
Member#: 225919
Join Date: Oct 2009
Location: Land of Kirk
Vehicle:
2000 2.5rs
Psh... F Kartboy brackets

Default

If you want to run 02 sensors for separate banks you will need to use an ecu that is compatible with a dual bank ignition system. In most 4cyl subarus there is only one bank for fuel trim control. The 02 sensor ahead of the cat will read the oxygen content of the exhaust stream and the ecu will either enrich or lean out the fuel trim. Some vehicles, typically ones with more than 4 cylinders, have separate fuel trim control for both banks separately. The 02 sensor post cat is purely for monitoring the cat. Thank you C.A.R.B.

So if you want to run true dual exhaust you will need a new ecu.

My suggestion would be to use a stock or borla or custom header and then split the exhaust into dual exhaust afterwards.

It may be possible to just monitor one bank of the motor. But I would think the ecu would recognize the reduced number of cylinders in terms of reduced exhaust gas. Then think it has a lean condition and either enrich the fuel mixture or throw a dtc for a lean condition.

One more idea, and you may have to talk to someone who actually tunes cars to verify, is that you may be able to tune your way around the problem, with a wide band controller or something of the sorts.
* Registered users of the site do not see these ads.
Teryn It Up is offline   Reply With Quote