Just bought the car off an old man.. The car is bone bone bone stock.. my first real bone stock car that i am gonna fix up yo... But anyways.. I swear my car has a 4 wire o2 sensor right in front of the motor. It has the same exhaust manifold as a newer 96-00 civic DX would have... It has the exhaust manifold and then the cat right in front of the car.. But yeah how come my car only has a 4 wire o2? *scratches head*

 

the o2 it self has 4 wires just like any other, but its where it connects to the ecu is where its 5 wire

 

Thats weird.. i've had an L1H1 (VX O2) before on my Techedge wideband and it had 5 wires coming straight from it... :confused:

 

I have owned 2 vx civics. Both o2 sensors had 5 wires coming out of them and both had the cat attached to the manifold in front. Make sure you motor is stamped d15z1.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lazie &raquo;</TD></TR><TR><TD CLASS="quote">the o2 it self has 4 wires just like any other, but its where it connects to the ecu is where its 5 wire</TD></TR></TABLE>
buzzzzz, incorrect. the L1H1 has five wires running out the top of the sensor.
(I'm holding one in my hands right now)

4 wires go to the ECU (P07) the ground goes to the thermostat housing to make 5wires. (a normal 4wire O2 only connects to the ECU with two wires, the other two are power/ground in the engine bay)

VNTEC: if the CEL is not on and there is only four wires from the O2 then they may have swapped in a P28/P06/P05 ECU to get rid of the need for the expensive O2 sensor.
They may have also removed the CEL light and simply ran a four wire O2 figuring it's better than nothing.
there is also the potential of a swapped engine.
either way four wire O2 on a VX is not stock.

 

What ecu are you running? Not throwing a cel I assume?