1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

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

Discussion in 'ECU's, Electronics, and Tuning' started by civicious, Jan 1, 2006.

  1. civicious

    civicious FüK-VTEC VIP

    Messages:
    9,855
    Likes Received:
    629
    Joined:
    Jun 15, 2003
    Location:
    Houston, TX
    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...
     
  2. GSRCRXsi

    GSRCRXsi Super Moderator Moderator VIP

    Messages:
    9,622
    Likes Received:
    345
    Joined:
    Nov 13, 2002
    Location:
    MD
    just get a 4-wire you asshole :p
     
  3. civicious

    civicious FüK-VTEC VIP

    Messages:
    9,855
    Likes Received:
    629
    Joined:
    Jun 15, 2003
    Location:
    Houston, TX
    [​IMG]

    Unless, of course, someone has a spare one they'd be willing to donate :mrgreen:
     
  4. jamesA

    jamesA Well known pissed off telephone guy VIP

    Messages:
    16,121
    Likes Received:
    1,019
    Joined:
    Aug 10, 2003
    hahaha

    I'll help you find a P08 if you sell me that p28 for 115 shipped. :p
     
  5. pissedoffsol

    pissedoffsol RETIRED

    Messages:
    49,693
    Likes Received:
    53
    Joined:
    Sep 28, 2002
    Location:
    Retirement Home
    dude, just go to autozone and pick up a generic bosch 4-wire o2. its the same shit.
     
  6. Taco15

    Taco15 I wear stretchy pants VIP

    Messages:
    6,998
    Likes Received:
    203
    Joined:
    Jan 11, 2005
    Location:
    Tallahassee Fl
    damn dude. Tell ya what...i'll send you a 4 wire 02 and you pay for shipping. hows that.
     
  7. SixtySecondAssassin

    SixtySecondAssassin Senior Member

    Messages:
    1,071
    Likes Received:
    0
    Joined:
    Sep 30, 2002
    Location:
    Austin, TX
    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.
     
  8. jamesA

    jamesA Well known pissed off telephone guy VIP

    Messages:
    16,121
    Likes Received:
    1,019
    Joined:
    Aug 10, 2003
    Taco rocks. lol
     
  9. civicious

    civicious FüK-VTEC VIP

    Messages:
    9,855
    Likes Received:
    629
    Joined:
    Jun 15, 2003
    Location:
    Houston, TX
    Lol...I'm chipping the ECU and keeping the 1-wire until I get a WB...


    Thanks though :thumbsup:
     
  10. Taco15

    Taco15 I wear stretchy pants VIP

    Messages:
    6,998
    Likes Received:
    203
    Joined:
    Jan 11, 2005
    Location:
    Tallahassee Fl
    all right fine. still gotem for a while so lmk if you end up needing them:lol:
     
  11. xenocron

    xenocron Member

    Messages:
    57
    Likes Received:
    0
    Joined:
    Jun 28, 2005
    Location:
    Bergen Co., NJ
    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)

     
  12. MikeBergy

    MikeBergy Blah blah blah....

    Messages:
    3,646
    Likes Received:
    1
    Joined:
    Oct 9, 2003
    Location:
    Central Coast, CALI
    Wow, I didn't know Chris was on this site too. Where have I been? Why didn't you just get a chipped pm6 :)
     
  13. civicious

    civicious FüK-VTEC VIP

    Messages:
    9,855
    Likes Received:
    629
    Joined:
    Jun 15, 2003
    Location:
    Houston, TX
    I got a P08. 1 wire 02 sensor + right ECU for my motor without chipping = t3h win!
     
Verification:
Draft saved Draft deleted

Share This Page