Converting a P28 to run a 1-wire O2 sensor...

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civicious

civicious

Buck Futter
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First of, don't tell me 'Just get a P08' or 'Just chip it!' I'm not getting a P08, and I'm not chipping it. I've read that there may be a difference in the fuel/timing maps on the P28 versus the P08, with the P08 being more aggressive, but I really don't give a shit as I'm not going to be racing anyone with the stock D15.

OK, I know that to convert a P05 to run a 4-wire O2 sensor, all you have to do is add a NPN digital transistor (C144) at Q30.

Now, I'm going to be running a P28 on a D15B in a 90 CRX...I've got the OBD0-OBD1 jumper that has the 4 wires for the O2 sensor, BUT the motor came with a 1-wire, and the CRX isn't wired for a 4-wire...The reason I'm running a P28 is because NOONE had a P08 in stock, and I got a virgin 5spd P28 for a great price from JHP...I'm planning on chipping the P28 this summer when I go turbo, but I am NOT chipping it until then (so don't tell me to just chip it and disable the O2 heater...I already know I can do this, but I'm NOT chipping this ECU yet.)

My question is this...If the only thing required to ADD the heater to the 4-wire O2 sensor is the C144 transistor at Q30, could I just REMOVE the transistor from the P28 and run the 1-wire O2 sensor without any problems? Also, will this affect VTEC engagement?


Thanks in advance...
 
damn dude. Tell ya what...i'll send you a 4 wire 02 and you pay for shipping. hows that.
 
sounds like a solid theory. give it a try!

the jumper harness should be ready to accept a 4 wire o2 sensor, you'll probably want to put one in sooner or later.
 
To throw some info out there, yes it only takes adding one transistor to a P05 ECU so that you can run a 4 wire O2, BUT, the program on the P05 ECU still thinks there is only a single wire O2 so you need to change the program (IE - chipping). Same with a P28. You can run a single wire O2, but the ECU needs to know that its a single wire (IE, the computer needs to be chipped so you can disable the O2 heater)

civicious @ Jan 1 2006 said:
Quoted post[/post]]
First of, don't tell me 'Just get a P08' or 'Just chip it!' I'm not getting a P08, and I'm not chipping it. I've read that there may be a difference in the fuel/timing maps on the P28 versus the P08, with the P08 being more aggressive, but I really don't give a shit as I'm not going to be racing anyone with the stock D15.

OK, I know that to convert a P05 to run a 4-wire O2 sensor, all you have to do is add a NPN digital transistor (C144) at Q30.

Now, I'm going to be running a P28 on a D15B in a 90 CRX...I've got the OBD0-OBD1 jumper that has the 4 wires for the O2 sensor, BUT the motor came with a 1-wire, and the CRX isn't wired for a 4-wire...The reason I'm running a P28 is because NOONE had a P08 in stock, and I got a virgin 5spd P28 for a great price from JHP...I'm planning on chipping the P28 this summer when I go turbo, but I am NOT chipping it until then (so don't tell me to just chip it and disable the O2 heater...I already know I can do this, but I'm NOT chipping this ECU yet.)

My question is this...If the only thing required to ADD the heater to the 4-wire O2 sensor is the C144 transistor at Q30, could I just REMOVE the transistor from the P28 and run the 1-wire O2 sensor without any problems? Also, will this affect VTEC engagement?


Thanks in advance...
Click to expand...
 
Wow, I didn't know Chris was on this site too. Where have I been? Why didn't you just get a chipped pm6 :)
 
I got a P08. 1 wire 02 sensor + right ECU for my motor without chipping = t3h win!
 
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