Reflashed...now having Secondary O2 sensor problems

PapiTuyo · Post by **PapiTuyo** » Wed Mar 23, 2005 11:04 pm

First off, i Own an EP3 and im recently swapped ecus for the hondata reflash (k20a3)

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? The other way around?

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.

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.

Post by **Spunkster** » Thu Mar 24, 2005 10:25 am

You probably bought a damaged ecu that had an improperly wired o2 sim on it. We do not recommend the use of any o2 sims as they tend to casue more problems than they resolve. If it is in fact a damaged ecu, there is really nothing you can do to fix it.

I would recommend removing the o2 sim as well as the A/F gauge and see if the error goes away.

PapiTuyo · Post by **PapiTuyo** » Fri Mar 25, 2005 2:58 pm

goign to remove the o2 sim and see if i get any voltage readout from the sensor, and then from wiring....

this should identify whether the sensor is dead, wiring is shitty, or indeed the ecu i bought was fried

PapiTuyo · Post by **PapiTuyo** » Sun Mar 27, 2005 3:02 pm

ok...my worst fears came tru

I spent yesterday, my birthday btw, checking the o2 sensor with the steps from the helms manual. I used a voltmeter and determined that the only option is a fried ecu. AH im soo pissed, what a sorry birthday.

Anyway, The ecu was indeed damaged by the previous owner and his shitty o2 simulator installation.

My questions:

1. How extensive is the damage caused by misplaced o2 simulator?
2. Can the ECU be repaired? Swapping chips possibly?
3. Im assuming i can upgrade to kpro on the ecu....so what are my options

Im so angry about this. I feel like the 400 dollars i paid for the reflash were thrown away. The previous owner has contact 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.

Is there anything that can be worked out with hondata? Maybe i can buy another ecu and send both and only get one back with kpro...what a shitty weekend

Post by **Spunkster** » Mon Mar 28, 2005 11:58 am

Your best bet will be to get your money back from the person that sold you the ecu and then just buy the K-Pro for your stock ecu. This will cost $995. If you want a new ecu, the price will be $1595.

PapiTuyo · Post by **PapiTuyo** » Mon Mar 28, 2005 12:21 pm

Spunkster wrote:Your best bet will be to get your money back from the person that sold you the ecu and then just buy the K-Pro for your stock ecu. This will cost $995. If you want a new ecu, the price will be $1595.

my stock ecu has been fried tho, by his incorrect o2 simulator installation..as soon as we swapped in the dealer, he got the same cel light he had before, even with my ecu.