I have a 1st gen b16a in my 90 integra. Ive posted about my header issues many times before but NEVER have i had a response. So here is a different question.

On the stock B16a 4-2-1 header, it has 2 O2 sensors, each is in the path of 2 cylinders (like O2 sensor 1 is for cylinders 1 and 3 and O2 sensor 2 is for cylinders 2 and 4. My question is, when i replace this header, do i need the 2 O2 sensors to be matched up the the flow the exhaust ports just like they are in the stock header? So i would have to have O2 bungs welded in the right spots? Or can i have 2 on the collector? Does it matter at all?

The reason I ask is its been such a pain in the *** to find a header that will work with my set up because I dont know anything about how i need the O2 sensors hooked up and what they will effect depending how how they are positioned or whatever

 

yes, it's very hard to find a header that has the dual 02 bunger holes built in to it, unless you go get a header customized with those 2 02 holes. A solution might be to have the ecu reprogrammed (if you're running a PR3 ecu). I have a mugen variant program which has disabled sensors -- disabled knock sensor, 2nd 02, and vtec pressure switch. This will make your issue much easier to deal with since only 1 02 sensor would be utilized by the ecu. contact me if you're interested, but I suggest you have a camshaft upgrade (at least type-R cams).

 

I have CTR cams and ITR valve springs and I just got a spoon program that gives 5500 vtec and 8700 redline. Im not sure how high I could rev but i think this chip will disable the second O2 sensor.