Civic VX lean burn

[ivicR]

interesting... all i really want to know is how to put it back to stock tho. =/
any one know where i kan get a wiring diagram that shows the wire colors and such. all i kan find is a diagram that shows where the plugs are and which plug is which.

that still doesnt make sense why theres a diode tho ?

[dwtaylorpdx]

There is some urban legend out there that you can "adapt" a wide band sensor to use in a standard sensor to handle radical engine changes better. Cant pin the logic down myself,, but a typical 4 wire setup has two black wires for the heater element in the sensor (interchangeable) , a white and a grey wire. ngk.com had a little diagram as well its under the 411 link.

Good Luck
Dave

[ivicR]

oh, i need more then the o2 sensor. since my engine harness was chopped, i need to know how to re-wire that. helms, haynes manuals are of no help either...

[dwtaylorpdx]

Ick, to be honest I'd find a U-pullit and extract the harness intact.
Most front clip harneses split out for the engine controls and are not
too bad to get out.

I've lost too many years of my life to tracing hacked car harnesses on race cars,
people do too much damage in the hack job and good luck finding the
damage inside the wrap.

I feel your pain...

Dave

[ivicR]

yeah, just that the VX harness has to be the most elusive harness ever !@ bleh. theres barely enough room left to splice it back together if i kan figure out what goes to what. what a head ache...

[mwebb]

Originally Posted by ivicR

yeah, just that the VX harness has to be the most elusive harness ever !@ bleh. there's barely enough room left to splice it back together if i can figure out what goes to what. what a head ache...

the actual Honda diagram is available on the Honda information website , there is a fee , but it is reasonable .

or
this is all i have on this laptop -

use the diagram with the red rectangle around it
for this application
use only an OEM Honda 02 sensor , do not use an aftermarket universal

there is a reason
the shielding on the thimble is incorrect on the aftermarket 02 sensors so the exhaust pulse from #3 cylinder causes a spike , so the 02 sensor appears to cycle every 720 degrees of engine rotation
the system will never be in fuel control
it will be difficult or impossible for a DIY type to track that down and solve it so
use only an Honda OEM 02 sensor purchased by the vin of the car for this application .

do not ask me how i learned this .
pain is a very good teacher .

should you require the waveforms to verify , just ask

[ivicR]

thanks for the scat.! I kant wait to get off work thursday and get under the hood.

[ivicR]

Ok, i finally got a chance to use the multi-meter at work.
reads 7.5K ohms both directions.
diode test reads 2.355vdc both directions.
So i guess its some sort of resistor..? still confused as to why it was needed.

[Whoops]

The problem your having is because for CA, as OEM's by Honda, they used a 4 wire oxygen sensor, CA specific controller and a CA specific transmission, all designed to make the equipment comply with the existing smog specifications, at the time of manufacture.

It is technically and as near as I can determine, physically possible to bring a VX into CA, after the fact and, if it is operating properly, get it to pass the CA smog requirements. What you have sounds like someone got a non-CA controller and jury rigged the wiring, instead of adding the additional wire that was needed for the 5 wire oxygen sensor.

If my understanding of what you are looking at is correct, you several choices.

First, get the documentation for adding a non-CA, VX controller to a non-VX vehicle. Then change the wiring to match the controller and then see if it will pass the smog inspection and testing.

Second alternative, get the documentation for adding a CA, VX controller to a non-VX vehicle. This will require getting a CA based controller and changing the wiring back to a 4 wire sensor. This will also require getting a 4 wire sensor, to work with the controller.

Third alternative, get a controller which matches the original vehicle type, change the wiring to the original and change the oxygen sensor back to the original.

Fourth alternative. In California, legally, the seller of a vehicle is responsible for making the vehicle pass the smog tests. If they can't do that, then legally they have to give you a refund of your money and take the car back.

[mwebb]

so , what does the EPA emissions tag under the hood identify the system as ?

OBD1 emissions, a 1995 could even be early OBD2

federal or California certified ?

Originally Posted by Whoops

The problem your having is because for CA, as OEM's by Honda, they used a 4 wire oxygen sensor, CA specific controller and a CA specific transmission, all designed to make the equipment comply with the existing smog specifications, at the time of manufacture.

It is technically and as near as I can determine, physically possible to bring a VX into CA, after the fact and, if it is operating properly, get it to pass the CA smog requirements. What you have sounds like someone got a non-CA controller and jury rigged the wiring, instead of adding the additional wire that was needed for the 5 wire oxygen sensor.

If my understanding of what you are looking at is correct, you several choices.

First, get the documentation for adding a non-CA, VX controller to a non-VX vehicle. Then change the wiring to match the controller and then see if it will pass the smog inspection and testing.

Second alternative, get the documentation for adding a CA, VX controller to a non-VX vehicle. This will require getting a CA based controller and changing the wiring back to a 4 wire sensor. This will also require getting a 4 wire sensor, to work with the controller.

Third alternative, get a controller which matches the original vehicle type, change the wiring to the original and change the oxygen sensor back to the original.

Fourth alternative. In California, legally, the seller of a vehicle is responsible for making the vehicle pass the smog tests. If they can't do that, then legally they have to give you a refund of your money and take the car back.