Senior Taco

Car: 99 accord ex 2.3L f23a1

I recently installed another o2 sensor (used) the heater on it must of been bad but before it threw a cel it was running MUCH better.

I decided i was going to trick the ecu into believing the ecu was fine with
some resistors ( 2 10 ohm 10 watt).

Well i had the wires all taped up so they would not touch i exposed one of the heater wires ( positive it turned out) to test it and it looks like a strand of the wire on the sensor ground was sticking out (it went through the tape) and the two shorted for a split second (i was very quick to rip em away from each other). The car didn't seem to act any different and the voltages were in check so i moved on and wired in the resistors.

I went to the advanced and checked the codes. I had the same codes which were heater malfunction but also a p0136 (O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)) pending I reset the codes and the car worked fine for a day or so and then it threw the p0136 again. I erased it again and it threw the light several miles later,after a day I checked the codes and I now got a p0137 as well (Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)).

Edit: the heater codes never came back up so.

What could be causing this?? did i short something?? can it be fixed ??
What do you guys think?

fcm

So you shorted the 12V+, [heated O2 sensor power] to the the sensors ECU/ECM lead, putting a full 12V+ into the ECU/ECM, I am pretty sure the ECU/ECM does not react well to that, even for a second. 94

GhostAccord

What O2 sensor did you add the resistors to, the primary O2 or the secondary? Because that error is for the secondary O2 sensor.

Senior Taco

Its all on the secondary o2 so that info is correct, my primary o2 sensor is good and reads as perfect.

By the way according to the Bosch sensor manual i touched +12v to (Ground Wire (optional)) and not the signal wire just so were clear on which wires crossed.

I would think that if the ecu was fried the car would react much worse?? (it seems to be the same, nothing outta the ordinary.)


And is there another board between the o2 sensor and the ecu ??

GhostAccord

Yes if you had shorted the ECU it probably wouldn't run at all. No there isn't another board between them.

What was the reason for adding the inline resistors?

Senior Taco

well my cousin pulled it outta path finder and i think the sensor its self is fine. but when i installed it, a few miles down the road it poped an error code for the heater.
I figured its either a bad heater or the heater isn't using as much juice as a stock sensor would. So I cut out the heater wires and hooked in some resistors that should simulate the stock heater's power usage.

GhostAccord

Senior Taco

Maybe i could make it easier. If i disconnect the o2 sensor all together and clear the codes, IF the ecu is fine will it still pop the p0137? cause i figure if its a short on the o2 or wires, if i disconnect them , then the short wont exist and i think id get a new code all together and not the p0137.. I assume that if it was the ecu, it would it pop the code no matter what right?