***Disclamers, Some these modifications are Illegal, and should not be done on any road going vehicles. This is for Educational purposes only!! If not properly implemented, changing an engines Air/Fuel ratio can have Catastrophic effects on your cars motor!!!***
This will be a short write up on how to install an Innovate Motorsport MTX-L wide band o2 sensor/controller in place of the original O2 sensor on a 92-95 Acura integra.
This will be almost exactly the same process on all OBD1 Honda/Acura 4 cylinder cars. (with the exception of the Civic VX**)
OBD0 and OBD2 cars will have to splice a different wire at the ecu.
The reason for doing this is multi purpose:
First, more accurate fuel metering on both stock and modified engines.
Second, the ability accurately to monitor fuel conditions.
***Third, the "option" of doing a lean burn conversion on a non lean-burn car
What you will need:
Various tools:
10mm wrench
Philips screw driver (No.2)
Flat head screwdriver
Wire crimps/cutters/strippers
22mm(7/8") wrench
Ect.
Innovate Motorsports MTX-L Advanced Digital Wideband Air/Fuel Ratio Gauge
2x Add a circuit fuse adapters
Wire of various colors (I used 16 gauge, it only needs to carry 3A)
5A fuse
1A fuse
Various Electrical connectors,
Zip ties
Optional:
Hole saw
Gauge pod/ some other way to mount the gauge
Heat shrink
10A 30OHM resistor
Lets get started,
1 Disconnect the battery. ALWAYS (I removed for ease of access later)
Remove some interior panels so that you can run wires from the gauge location to the ecu.
I decide to mount the gauge in the location of the factory interior dimmer. I did because it looks good in that location, i never change the brightness of my instrument cluster, and mainly because I broke it trying to take it out
Insert the gauge, and drop the wires down
I have quick disconnects, so that i can use the gauge to tune other cars occasionally.
Next run a wire from the red lead to a fuse on ignition switched power.
Then repeat the process for a fuse on the park light fuse for the wight lead.
Add a ground wire (to the black lead)
Then run a wire from the brown lead, over to the ECU.
Remove the ECU
On almost all OBD1 Hondas, the wire you are looking for is White with a red tracer, and will be pin#14 on the "D" connector. This will be wasy to find dueto the fact that it is one of the only wires with a Radio frequency shielding on it.
Splice into the wire and connect the Wide-band controller to the plug side of the wire. I used spade connectors so that i can return the car back to factory easily if need be.
Now, run the Wide band harness from the Gauge, through the firewall.
I used one of the factory holes/grommet located next to the battery. It should be noted that i did have to feed the wire FROM the outside because one plug is substantially larger than the other.
Double check your wiring!!!!
Now, you have a few options,
Either install a resistor to trick the ECU into thinking that the original (heater circuit) is still there
Or keep the original O2 plugged in and zip tie it under the car somewhere safe. (what I did)
Or disable the heater circuit by reprogramming the computer. However, that is a whole thread on its own.
Remove the Factory o2 sensor.
Before installing the new sensor It is important to calibrate it.
Connect the battery
The calibration procedure requires that the oxygen sensor be in free air, this
means removed from the exhaust system completely.
1. With the sensor disconnected, apply power to the MTX-L.
When power is applied, all three digits will light up and the needle bar will
sweep once through all LEDs. Then the status light will turn red and the
numeric display will read “E2”. This is an error code, indicating that no
sensor is detected. Leave unit powered on for minimum 30 seconds.
2. Power down the MTX-L and attach the oxygen sensor using the
cable provided. When making these connections, make sure they
are fully seated and locked. Again, make sure that the sensor is in
free air (not in the exhaust).
3. Power up the MTX-L.
Again, the display should ‘sweep’, but instead of an error, the display will
display “Htr”. This indicates that the sensor is being heated up to
operating temperature. After 30-60 seconds, the display will switch from
“Htr” to “CAL”, indicating that the sensor is being calibrated. A few
seconds later, your MTX-L will begin displaying AFR. Since the sensor is
in free air, the gauge will default to the upper limit of 22.4.
Done with calibration
Remove the battery.
Screw in the new sensor.
As a note the Sensor should be at least 24 inches downstream of the exhaust port outlet.
Re connect your ECU,
RECHECK THE WIRING.
Reconnect the Battery.
FIRE IT UP!!!
If all things Work out, putt the interior back together, and take it for a drive!
At this point, you have a basically Have a more accurate Narrow band. If you want to go the lean burn route, you will have to plug the Wide-band into a laptop and and boot up the Logworks3 software from Innovate Motorsports (included with the sensor) I will not be going into detail on how to change those outputs, but I will say that the software is very easy to use and that I changed the voltage switching point so that it outputs the equivalent voltage of 14.7:1 at 16:1 Just a little lean, but under load, it ignores the O2 sensor and runs off the mapping of the ecu anyway.
Once my MPGuino comes in, I will be doing an A-B-A test at 60mph Cruising at a few different AFR'S. I will need to be able to tune the ecu (coming soon) to change the ignition timing to really take advantage of Lean burn.
Technically, you "could" program the Yellow Output wire from the Wideband to interface withe the Civic VX ECU as the the LAF ECU input ("D" connector pin #16) however, you would need to find the Voltage curve for the VX sensor... good luck.
Feel free to ask questions!!!.