team 15

How come my 97 civic dx engine harness have both primary and secondary o2 sensor and my 97 civic ex engine harness don't have the secondary o2 sensor, but the primary one? Plus my 99 civic ex engine harness don't even have the secondary o2 sensor only the primary one. Does the ex engine harness come with secondary o2 sensor or not?

Padawan

The EX has the secondary sensor located under the car near the shifter, so it plugs in there through a hole in the chassis.

team 15

I did a swap. D16y8 to a 97 civic hb. It's throwing code for the secondar o2 sensor. How would i solve this problem?

Padawan

Well, the obvious answer (and I don't mean this sarcastically) is to wire up the secondary O2.

team 15

How would I wire up the secondary o2 sensor if the engine harness doesn't have one. Can i wire it to the primary one?

blackKready

the DX harness has the secondary O2 wired right into the harness. the EX harness , the secondary O2 sensor is not ran in the main engine harness. its in the dash harness. so you need to run new wires from the ecu to the secondary O2 sensor. find the proper pin locations , pin the wires , and run them to the sensor.

Padawan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackKready &raquo;</TD></TR><TR><TD CLASS="quote">so you need to run new wires from the ecu to the secondary O2 sensor. find the proper pin locations , pin the wires , and run them to the sensor.</TD></TR></TABLE>

Just what I was in the process of writing.

pdiggitydogg

^bingo
your pinout for an obd2a ecu is here:
http://technet.ff-squad.com/wiring.obd2a.htm

Snag some ecu pins at a junk yard and insert them into the connector clips

team 15

Thanks man. I will rewire the pin.

yee SERIOUS

iTrader: (1)

i gotta do this for my car too. sucks. has anyone tried wiring up the secondary o2 sensor to the ecu, but leaving the the o2 sensor just wrapped up in foil? someone told me this works, but im not too sure.

ifIexplode

Cant you just extend the wires from the DX secondary o2 sensor to the Cat

pdiggitydogg

you have to reread...
he is using an ex harness
ex harness has 2ndary o2 wires on the dash harness, not engine harness

tbuck4224

I could be wrong but im pretty sure the secondary o2 has to read a flow so you can bung the o2 raising it mostly out of the exhaust flow so it doesnt read anything shitty in the exhaust that would normally trip a CEL, but it is still in the exhaust flow so it doesnt trip the CEL for having no flow. Someone back me up... a friend of mine did it on his E36 M3 and it worked but if foil works too thats probably cheaper lol