HondaEm1-00

i have a 00 civic si . i have done everything to car i could imagine. until working on my 02 sensor. took 02 sensor out to clean it. i reached from the top of engine to the front 02 sensor to pull out. my jack is out of service. so after putting on i used pretty thick gauge wire hooked all up etc. go to car to start and wont. im like wait what this most reliable car ever. so plug scanner in and get p1607 ecu control internal circuit malfunction. also p0113 intake air temp circuit high p0118 engine coolant temp circuit high. so im assuming the 02 sensor goes into this ground as well so possibly shorted something blew a fuse. computer was just purchased on ebay and fully tested no problems been like a champ but until doing this job all of a sudden car will run for half second and back fire and die. im assuming maybe i disconected a ground from engine or a fuse or any kind of help please. i replaced all these things recently so i know there not bad and no meter to check voltage. from what ive stated any help on where to look or do i unhooked the 02 sensor just in case was wrong wiring or to thick gauge wire just reversed the thing ive done. but a computer failure now just isnt right.

HondaEm1-00

can some one pleasssssse help every time i screwed wiring i would get the other sensor codes but i would never get a ecu code. just dont believe it a bad a ecu. possible but any help please car is useless right now

Former User

Give some background on the car. How did the problem start?

If you reset the ECU, what codes return?

HondaEm1-00

car has the original head but b18 block been running fine. until got 02 sensor code for heater. rewired the 02 sensor and got high voltage signal. so i decided to soder and do the wiring corectly and use bigger gauge wire etc. after finish go to car and no start. can get started with w open throttle but will sputter back fire etc. so i get those codes. checked every ground in engine and reversed my steps to make sure i did not break any connections etc. and all looks good. i have done the cfk bypass trick on computer in past as well as a switch from the fuel pump by ecu etc. so i checked my ecu and all the wires i snipped in past and all looks fine no broken connections etc. so after taking terminals off and leave off still same thing after i clear codes. the same thing so just weird that my ecu went out from other day coming home to working on today and try to start and get this. so makes me think a short somewhere or bad ground or something.

HondaEm1-00

i even have computer open right now after reading its bad soder or something and i dont know if can tell by looking but everything is fine looking. key word lookiing though.

Former User

Your wiring is clearly suspect.

HondaEm1-00

ya i do believe that to. but where to start where ecu plugs in is only place ive performed splice jobs. they all look great. only thing i can think of would be my previous 02 sensor fails that led these codes to happen but never a failed ecu. so weird even after unpluging the 02 im still seeing these codes which is odd i even unpluged my fuel kill switch and rehooked up normal to get rid of this. im on the boat to go get a ecu but would hate to waste the cash. hmmm stumped.

tony_2018

Where to start?! its quite obvious you probably tapped into something you shouldn't have. Show pictures of your soldering work and some detail background of this car. If you have high output errors that means some wires are touching something it shouldn't be and is causing the ecu to see high voltage to those sensors. You need to pull that engine harness off and check to see nothing is either melted or making contact with another wire that is bare.


Edit: not to mention the certain o2 sensor wires are shielded so you better check that.

tlarimer

iTrader: (3)

If I remember correctly:

2000 Civic Si/EM1
B18C1 block/B16A2 head/Poorman's type R
Converted to OBD1 by previous owner
You converted back to OBD2

So my questions:
Are you running the correct OBD2 engine wiring harness or OBD1 engine wiring harness?

Why did you perform CKF bypass?

Why did you hard wire 2nd O2 sensor instead of plugging it into the underbody O2 sensor connection on the passenger side?

We need to know exactly what you have, what you are using, what you replaced to convert it back to OBD2?

The sooner we get a detailed description of whats been done, we can help you figure out whats wrong and how to repair it.

HondaEm1-00

thanks for the help guys like was saying everything was fine. i replaced ecu and works fine again. was just a bad ecu i guess just weird. but car runs better also so must of been a faulty or going out ecu and wiring must have made it finish. idk lol but new ecu no problems thx again guys. and the si harness i had on before to answer question had conversion harness for a chipped computer to run harness was still my si harness. but ya just weird. thanks.