NatedoggAZ

I am needing to convert a 4-wire harness to hook up to a 1-wire O/2 sensor.
I have a D15B Vtec using a P08 ECU. I have heard that the P08 will only understand the 1-wire O/2 sensor and my harness has a 4-wire plug.

I found this link: http://www.hybridautomotive.com/tech/o2/#one
not sure if it applies to my SOHC OBD1 Vtec engine though...

Can anyone confirm that ths information is correct and that this will work?

Thanks!

N8Dogg

NatedoggAZ

anyone?

NatedoggAZ

TTT - someone has to know, or at least confirm?

DaveSi

Sorry never heard of having to do that before but I would say just run the one wire from new O2 sensor to the signal wire at your ECU. Did that motor come with a 1 wire O2 in the exhaust manifold?

I am interested to hear what comes of this, I have never done that swap before.

NatedoggAZ

Yeah - the motor came with a 1-wire O2 sensor and I had to get a new harness since the one it came with was cut. The new harness uses 4 wires for the O2 and I dont think I can just plug then in together...

I know there have been a lot of people on HT that have done this swap, but not sure if the issue has been addressed or not since I cant find any verification.

MikeNice

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NatedoggAZ &raquo;</TD></TR><TR><TD CLASS="quote">
I am needing to convert a 4-wire harness to hook up to a 1-wire O/2 sensor.
I have a D15B Vtec using a P08 ECU. I have heard that the P08 will only understand the 1-wire O/2 sensor and my harness has a 4-wire plug.

N8Dogg</TD></TR></TABLE>

No man. The P08 is a OBD-1 DX computer and will only understand 4 wire 02 sensors. And if your motor is VTEC then your using the wrong ECU since the P08 is a non-VTEC ecu. I would suggest getting a p28 kid.

NatedoggAZ

I have never seen anything that says the P08 is not a VTEC ecu...

I just read a post from HT member: eg6ajk

here is what he had to say..

"P08 has the same codes as P28 and any sohc vtec d-series ecu NO KNOCK SENSOR
with an exception in :
- no code 41 which is the heating element
- no code 13 which is a BARO (PA) sensor

that tells me that is IS a VTEC ECU...

MikeNice

of course they have the same codes, they are all OBD-1. Even if you had a B-Series motor the codes would be the same as long as its OBD-1.

All are OBD-1
p07 is a CX ecu
p08 is a DX/LX ecu
p28 is an EX ecu
p30 is a JDM OBD-1 B16 ecu
p61 is a 1.7 GSR ecu
p72 is a 1.8 GSR ecu
p75 is an LS ecu

all will plug into your 94 CX.

EE_Chris

Can you plug a 1-wire O2 sensor into a 4-wire connector....nope, so one thing that needs to be done is to get a 1-wire connector and solder it onto one of the 4 wires...the white one should suffice.

Now that you are able to connect the 1 wire O2 to your wire harness, is the actual O2 signal getting to the ECU? Which ECU pin on the P08 is the O2 input? The white wire that you are now using for the O2 signal terminates somewhere in one of those ECU plugs, right......so now you have to move the white wire into which ever spot it needs to be on the P08 ECU connector.

So maybe I'm missing something, but it seems as easy as getting a new connector, grating it onto your exisitng wire harness and perhaps move a wire at the ECU connector to get the O2 signal into the P08 ECU.

NatedoggAZ

Thank you for your help with that one - I am gonnt try and see if that will do it.

oh, and for MikeNice - the P08 info: P08 : 92-95 OBD-1 Civic/CRX VTi/VXi (sohc vtec)

ECU identification: http://pgmfi.org/resources/FAQ/identification.html

EE_Chris

What do you mean they all share the same code because they are OBD1?

Are you suggesting they all share the same fueling and timing maps?

Honda_Tengoku

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MikeNice &raquo;</TD></TR><TR><TD CLASS="quote">

No man. The P08 is a OBD-1 DX computer and will only understand 4 wire 02 sensors. And if your motor is VTEC then your using the wrong ECU since the P08 is a non-VTEC ecu. I would suggest getting a p28 kid.</TD></TR></TABLE>

The P08 is definately not a DX ECU. The DX ECU is a P06. As far as the one wire o2 goes, the only one that has it that I am aware of is the P05 CX ECU. In my D16Z hatch I believe I did have the P08 ECU from what I remember(dont quote me on it). It definately had VTEC, and was a 4 wire o2. I can talk to the guy who owns it now, and ask him to make sure.