O2 Prob or just a rotten ecu ? Helpp

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vtecjdm

Senior Member
Running a p28 with a sohc vtec motor.

Only code i`m getting is an o2 heater sensor code obviously cause my sohc uses a 1wire o2 sensor.
I was gonna get a 4 wire to match the p28 but i donno if the prob is coming from the o2 thing, and dont wanna buy a 4 wire o2 for nothing.

The prob:

The car revs normally but will just hit the max at 4000revs. Is the ecu goin into limp mode ?
Will an o2 sensor prob make the ecu into limp mode cause i never heared anything like it here or is it that i got a fucked p28 ?

Somone please confirm ?

Thanks
 
i really dont know what else will fit it, but i can tell you 99.9999999% its not your ecu. 1 in a million go bad.
 
i'll get you one today. I'll ask how mich my buddy wants for it.
 
Haa .. finallly found a 4 wire O2.

Now my Q is ... if i re-swap my other ecu back in (the one that uses 1 wire O2 sensor) .. will this new 4 wire sensor work with it too just by ignoring the other 3 wires ? Or i have to re-swap back the 1 wire sensor i had ?

Hmmmm :huh:
 
Yeah got it .. but i was asking if a 4 wire o2 can be used with an ecu which takes a 1 wire o2.

Is it possible to just ignore the othe 3 wires ?
 
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Yeah got it .. but i was asking if a 4 wire o2 can be used with an ecu which takes a 1 wire o2.

Is it possible to just ignore the othe 3 wires ?
i actually thought of that a couple days ago. I really dont know but i wouldn't do it. the reason being is that the heater control needs to be grounded...2 wires. then you need the o2 signal.....3 wires. hell let me put it this way DON'T DO IT. :mrgreen:
 
Well hold on a sec.. on a 1 wire ecu (like some jdm ones) .. the only signal you need is the o2 sender wire (white i think).. no heater shit so ... basically i think you would be only using that wire and just forget all about the heater cause the ecu wont need it.
I `presume`a 4 wire sensor could be used instead of a 1 wire sensor. Please correct me if i`m wrong on this .. :huh:

Obviously doing the opposite is impossible :)
 
The heater is in teh 4 wire O2 sensor to keep the sensing element up to temperature. If you don't wire it up, the sensor may not be at operating temperature and hence will give duff readings. Since your ecu is only as good as the reading it receives, why not just do it properly?
 
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The heater is in teh 4 wire O2 sensor to keep the sensing element up to temperature. If you don't wire it up, the sensor may not be at operating temperature and hence will give duff readings. Since your ecu is only as good as the reading it receives, why not just do it properly?
yeah same here. do it right just to be on the safe side :)
 
Yeah thats true most prob the sensor wont work as well without the heater connected (even though i think theoretically it would work, but maybe the readings would be sligtly off ) //..anyone wanna try :)
Thanks guys :)
 
i alsmost did. When i tried to go odb1. i ran the 4 wire o2,ran the new vtec wires from the harness. I fucked up and hooked the wrong dizzy wires and the car would not start. So when i gave up a i thought about it.....but didnt do it. Its safer to just to it right.
 
Ok guys .. i`m getting a 4 wire o2 for the p28.
However no one here gave me an answer about why the car wont rev over 4000 ... i`m only getting an o2 heater code, SOO that must be it ... but i never heared anyone say that a simple o2 heater code would make the ecu do this.

Anyone confirm or disconfirm ? :huh:
 
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