I have a jdm b16 and i need to know which is the primary and which is the secondary. right now i think i have the one on my right side as the primary. I have the stock exhaust manifold which places the o2 sensors behind the header. can anyone tell me if it makes a diffrence???

 

knock, knock...is this thing on?

 

Yes it does make a difference..
Wire them like this:



Modified by 88DXCRX at 7:14 PM 4/5/2004

 

so the green one is the primary? c16

 

that is correct!!!!!!!!!!

ding ding

a winner everytime

 

The o2's are not heated, and I don't understand how you would define a primary. Being there both in the same spot on the header. An as far as I can remember they run as 1-4, 2-3. So how would you say there is a primary there. They are in the same spot, there not heated, and as long as there wired up properly its going to work! Put it to you like this, you can stick them in to either hole its going to work, sorta like a girl . They both get the same readings because there both in the same spot on the stock header. This means no matter where you stick them as long as your ecu is wired up properly it won't matter. If you want to call the green plug the primary fine, but it won't make a difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxirex &raquo;</TD></TR><TR><TD CLASS="quote">The o2's are not heated, and I don't understand how you would define a primary. Being there both in the same spot on the header. An as far as I can remember they run as 1-4, 2-3. So how would you say there is a primary there. They are in the same spot, there not heated, and as long as there wired up properly its going to work! Put it to you like this, you can stick them in to either hole its going to work, sorta like a girl . They both get the same readings because there both in the same spot on the stock header. This means no matter where you stick them as long as your ecu is wired up properly it won't matter. If you want to call the green plug the primary fine, but it won't make a difference.</TD></TR></TABLE>

It most certainly makes a difference.

Primary - C16 - 1-4 bank on the manifold.
Secondary - C8 - 2-3 bank on the manifold.

The OBD0 PW0/PR3's are oddball ecu's. AFAIK, they were the only ecu's to require two O2 sensors, with one sensor on each exhaust bank on the manifold. From my understanding it's almost like running two seperate ecu's, as the ECU monitors and supplies fuel idependantly between the 2 O2 banks. It definitely makes a difference to hook them up correctly.

For instance,

(Right way)
The 2-3 cylinders go a bit lean, 2ndary o2 sensor reads lean condition, ecu supplies more fuel to 2-3 clinders.

(Incorrect way.)

The 2-3 cylinders go a bit lean, primary o2 sensor reads lean condition, ecu supplies more fuel to 1-4 clinders. 1-4 cylinders go rich, 2ndary O2 sensor reads rich condition, ecu leans out 2-3 even more when they are in need of fuel.


There's more info on this if you search the archives. It's where I got all my info when I had this issue with my swap.

 

I just don't know. I just can't understand why it would make difference being there both in the same spot on that header. An besides, they are running in pairs.
Hmmmm, its kinda weird but whatever, obd1 is the way to be lol.

 

Look closer, they are not in the same spot. They both only see 2 cylinders each.

 

there pretty close . Idk I went obd1 right away anyways, I saw my header for like 2 min and threw it in the trash.

 

Uhhh...if they were in the same spot, then they would be overlapping eachother. Your brake pedal and your gas pedal are really close to eachother, but each does something different doesn't it?