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Discussion Starter · #1 ·
First off, i Own an EP3 and im running the hondata reflash

Ive been having some issues with my secondary o2 sensor. I had been running caspers simulator on my dc race header for over 9 months w/out a problem. I recently swapped ecu's with another members and ive gotten an o2 sensor malfunction CEL. I kept the race header and kept casper's sim. I have a couple questions.

1- Is it possible for the ECU to have fried my o2 sensor?

I dont see this as a likely possibility, but the Honda guy who reflashed my immobilizer suggested this might be the cause....The odd part was that i had NO CEL prior to him reprogramming the immobilizer.

2- Is there a possibility that the hondata-ed ecu is faulty? Could just my secondary o2 sensor port be faulty?

My A/F guage stopped working as soon as I swapped ecus. I had it wired correctly and It no longer reads anything. It read everything correctly prior to the ecu exchange.

If my ecu was faulty, and my o2 sensor was still ok, then I would technically still be recieving data from the sensor correct? The fact that im recieving no signal anymore signifies that my sensor needs to be replaced...right?

3- Does anyone have a wiring diagram for the sensor itself? I havent inspected the sensor yet, as I live in the dorms and its a PITB to work on my car w/out proper tools.

4- Does anyone have a spare secondary o2 sensor?

I need the advice of people whove experienced similar sensor problems. I have grounded my ecu properly as per Hondata's website. Lookin for help, thanks.

i just checked the CEL light with the DIY LIGHT GUIDE

6 long blinks 5 short ones

thus...

P0141
11-68

Description
Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) Heater Circuit Malfunction


Im guessing its just not getting a reading then huh...someone who knows their electronic crap please chime in.
 

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Two problems here. One is the heater circuit and one the O2 sensor itself. I would firstly check that there is an output from the sensor. Disconnect the plug and with the engine running check for voltage across the sensor pins (not the heater wires). No voltage = dead sensor. Check the O2 heater resistance (should be anywhere from a couple of ohms to around 11 ohms when hot). If you get nothing then the heater circuit has cooked. I'm guessing that the sensor is dead. Highly unlikely that the ECU caused this since you didn't change the wiring only the ECU. If the ECU detects a fault in the heater circuit then it ignores any output from the sensor.
 

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Discussion Starter · #3 ·
I spent yesterday, my birthday btw, checking the o2 sensor with the steps from the helms manual. That lil PDF file is incredibly useful. Its is very comprehensive. If anyone needs one, pm me and ill hook you guys up. Anyway, I used a voltmeter and determined that the only option is a fried ecu. AH im soo pissed, what a sorry birthday present, a blown hondata ecu :(

Anyway, I later found out after working on the car for a few hours that the ecu was indeed damaged by the previous owner and his shitty o2 simulator installation.

My questions:

1. How extensive could the damage be that caused by misplaced o2 simulator?
2. Can the ECU be repaired? Swapping chips certain chips?
3. Im assuming i cant upgrade to kpro on the ecu....so what are my options :(

BTW i posted on Hondata's board as well...Im giving them a call tomorrow :( :( :(

Im so angry about this. I feel like the 430 dollars i paid for the reflash were thrown away. The previous owner has contacted an ECU repair shop and they say they can replace the blown chip. Hes offering to pay for the repair, but my concern is that the o2 simulator might have caused undetected damage. Im afraid to get a refurbished ecu upgraded to kpro and then realize that its still damaged.

Is there anything that can be worked out with hondata? Maybe i can buy another ecu and send both and only get one (the undamaged one) back with kpro...



AHHHHHHH...what a shitty weekend
 

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Firstly take the board out of the ECU and make sure that the secondary O2 pins have continuity to the board itself. Then go over the board with a magnifying glass looking for any signs of a melted component. These boards are generally speaking not repairable. To many surface mounted components. But in your case why worry. Get the K-Pro and just disable the OBDII. The secondary O2 sensor is only there to check that the CAT is working. It has no bearing at all on performance. As long as the primary O2 sensor is working then you're good to go. If you're still not happy I'll offer you $100 for the ECU...
 

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Discussion Starter · #5 ·
worked things out

hondata is the shit

if anyone has a spare k20a2 ecu, please let me know
 

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so what was the prob? how did you work it out?
 
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