Civic-EG.com Forum 3.3.1

- Mon Apr 04, 2011 6:55 am #248151 My car is throwing a code 41 in my b18a1, is the oxygen sensor heater the O2 sensor located on the header?

- Mon Apr 04, 2011 10:36 am #248162 yeah, the O2 heater is internal in the O2 sensor and is located on the header

- Mon Apr 04, 2011 8:19 pm #248245 Thank you very much that is what I thought I just was not sure if there was more than 1 oxygen sensor.

- Mon Apr 04, 2011 8:25 pm #248253 if there was another one, it would be after the cat...just look to see if you have one plugged in there or not

- Mon Apr 04, 2011 10:27 pm #248279 There wouldn't be a second O2 sensor. It's a B18A1 in an OBD-I Civic.

The O2 sensor heater circuit is part of the sensor itself. Replace the O2 sensor, and the code will go away.

Hi, I'm John. I'm a hacky sackin', rock climbin', scuba divin', aircraft mechanic.

- Tue Apr 05, 2011 6:16 pm #248539 Okay I think the sensor itself is still good, just when I changed the header my dad cut the wires because there was no plug in just someone tied them before I got the car and my dad retied everything but maybe he did not connect the wires good enough.

- Tue Apr 05, 2011 6:42 pm #248543 use solder and heat shrink!

- Tue Apr 05, 2011 10:24 pm #248580 I have a slight problem now the sensor itself has 2 blacks 1 with a white line and 1 green and 1 white for a total of 4, from the car there are 2 blacks 1 green and 1 white. Does it matter if the 2 black gets mixed up I heard the green is signal the white is ground and the 2 blacks are the heater, I heard the blacks have no polarity.

- Tue Apr 05, 2011 11:01 pm #248583 Typically, black wires are for ground. I'm guessing the two black wires on the O2 sensor are the returns/grounds for the heater circuit and sensor circuit. I imagine that the sensor side would be critical considering the return from the sensor goes to the ECU to give input for fuel trim adjustment.

Hi, I'm John. I'm a hacky sackin', rock climbin', scuba divin', aircraft mechanic.

- Tue Apr 05, 2011 11:13 pm #248586

I have a slight problem now the sensor itself has 2 blacks 1 with a white line and 1 green and 1 white for a total of 4, from the car there are 2 blacks 1 green and 1 white. Does it matter if the 2 black gets mixed up I heard the green is signal the white is ground and the 2 blacks are the heater, I heard the blacks have no polarity.

yes and no...it depends on the manifacture, find out who made the O2 sensor and see if you can find the wiring diagram from their web page or something...

i had a bosh and the ground was grey not black

- Fri Apr 08, 2011 4:57 pm #249152 I just replaced the old sensor with a new one but the car still idles lower, any ideas? or will the car adjust overtime, and I will reset the ecu if that will help.