My coworker is selling a DC header (CARB legal) from a 99 Civic w/auto tranny. Would it fit on my 90 Civic w/ manual tranny & D15B1? Is there an O2 sensor bung for the pre-cat o2 sensor like the OEM manifold? I only want it because it has the CARB badge still and my OEM exhaust manifold is cracked/leaking and SMOG is due.

Thanks in advance.

 

not sure about the fitment but pretty sure you are going to have to lengthen your o2 wire coming from the engine harness, since the new o2 will be close to the rear cross member and the stock location in the ef is on the front of motor in the header.

 

You absolutely can NOT do this with the O2 sensor. Single wire O2 sensors must be heated by the exhaust gas to operate properly. When it is placed downstream near the catalytic converter, the exhaust gas has already cooled too much for proper readings. This is the same reason single wire O2 sensor vehicles don't read the O2 until "operating temperature" is achieved. The only work around is to wire in a heated O2 (3, 4, 5, or 6 wire) for proper operation.

OP - Before you purchase the header, be sure it has an O2 bung near the head and not just by the collector.

 

thx for the clarification.

 

...or take the header to a good welder and weld O2 bung into the #1 runner.

If you are running or ever intend to run a JDM B16, the proper way is to weld two O2 bungs and use two O2 sensors in your header. One will be on the #1 runner and the other will be on the #3 runner.

I ran an ITR header for years in my OBDO 202whp B16 CRX with no codes and got 28-30 mpg.

 

im sure the dc header has the o2 censor at the rear end of it wat you should do is weld a bung on the 4th runner near the top and just plug your o2 there and other than that it will fit fine you might have to modifiy your stock pipeing