So 96 civic dx d16y7. Aftermarket header, therefore no cat. Im wondering since the upstream and downstream o2 sensors are more that likley reading the same do I really need the secondary? I only ask since the old one thats there isnt even wired up, the wires have frayed apart and actually wore through. I dont want to buy a new one or go through the money of wiring it back up if need not be. I recieved the car like this so obviosuly cant realize a change in performance as this is how i got the car. Im planning on going turbo as well if this changes the equation. Thanks guys I do appreciate it. HT 4 Life!

 

yes youll need the secondary because your ecu is looking for it and probly throwing you a CEL? thats the only way to get the CEL gone or you can probly have it taken out thru modding your ecu.

 

Hmm. I went to a friends house arlier today and he wired it up for my and plugged it in a open plug in an it fit and all but it still has the cel on. I should probably get it scanned. Is there some kind of diagram anyone has to make sure I have this thing plugged in the right spot? Thanks again.