SOHC VTEC ZC w/ P70 ecu, o2 sensor problem

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mjshealy

New Member
hey all, i swapped a sohc vtec ZC into my 94 civic vx hatch, and have a P70 running it. I keep getting a code 1 (heated o2 sensor), but there isn't a heated o2 in any (that im aware of) JDM 92- 95 civics. The ZC came with a 1-wire o2, i have since replaced it twice with a CX (1 wire) o2 sensor, pinned directly to D14 on the ecu. It still pops the code everytime, even after resetting the ECU. Can someone please tell me what the hell is going on? after 6 months and various posts on various forums, i have had no one reply with any helpful advice other than "there's no such thing as a sohc vtec zc". If anyone has a SOHC VTEC ZC, PLEASE post and let me know which ECU and what wire o2 sensor you are running. Thank you.
 
SOHC VTEC ZC=D16Z6. You're getting a code because the ECU is looking for it, has nothing to do with what came on the motor. Wire in a heated o2 sensor(4 wire) or get the jdm ecu.
 
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ok, i will try to wire the 4 wire in with the p70. When i was on the phone with the guy in japan, he assured me the motor required a P70 ecu and it took a 1-wire. He seemed very knowledgable and very asian, but he could have been wrong i guess. It's just weird because the motor came with the exhaust manifold, which included a 1-wire o2. I will see if i can find one of the 4-wires i have laying around in the box and try it.
 
From what I've seen, all the JDM motors do indeed have 1-wire O2s. Have you checked the grounds?

Another option would be to use a P28 and swap in a 4-wire O2.
 
yes, the motor is grounded and connections are tight between the valve cover and frame. I cannot find the 4-wire that i had new in box, but i remember trying the p28 with 2 brand new 4-wire o2 sensors and could not get them to work either. I believe it was the same code too, a code 1.
 
Valve cover and frame are the only ground? Check the thermostat ground; and make sure there's a good connection between the grounding strap and frame that's on the transmission.
 
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