How To Discover If You Have Wideband Or Narrowband O2 Sensors

How Do I Know What I Have?

That is one of the most commonly asked questions by our customers. It can be confusing because many times, even the guy at the Parts Dept of your service center, and even many mechanics, have no ideal how to tell the difference between them, or can even tell you what you have. But not to worry; we can show you the easy way to identify what your car has.

The Wideband and Narrow Band Sensors are not compatible and you must choose the proper TUNER for your car.

NOTE: MOST poor results can be traced to an incorrect installation of the EFIE using the wrong sensor wire- double check yours by the method below!

FIRST - Try The EASY Method:

Click on this link to open a new window to and look at the top of the page

  2. Now, Click on "REPLACEMENT PARTS" TAB to go to a new page
  3. "SELECT A CATEGORY" (You should see a long list of parts)
  5. Then "OXYGEN SENSOR"; a selection of sensors for your vehicle appears

You will see Part Number, Warranty and then "APPLICATION:" and you will have your choice of either a Down-Stream Sensor, or an Up-Stream Sensor.

ALL down-stream sensors are narrowband, no matter which vehicle.

We want to know what your "UP-STREAM SENSOR" is! FInd the first one on the list and click on it to go to detail page. Scroll down past the "Features and Benefits" section, and look for "OXYGEN SENSOR TYPE" It will tell you if it is Narrow-Band or Wide Band (heated or un heated doesn't matter to us).

Jot down what you need and you are READY TO ORDER an EFIE! Click this link to go back.

This will tell you what most vehicles sensor is. 

If they Do NOT have your vehicle part, you can try a different online store. You can also try to call your local dealership or auto parts store and tell them you are looking for a new set of Oxygen sensors for your car - the front ones. They can look it up for you- ask if those are wideband or narrow band sensors, but be aware, most parts guys will have no idea what you are talking about - LOL.



If none of these options are available, you'll need to locate the oxygen senor and then locate the signal
wire by testing. The sensor can have 2, 3 or 4 wires (some can have 5 or 6- these are rare), and you have to know which one is the signal wire. The most common configuration for modern cars is 4 wires.

If you have 4 wires they will be:
" Heater 12 Volts +
" Heater ground
" Oxygen sensor signal +
" Oxygen sensor signal ground

If you have 2 or 3 wires, then you can have a common ground, or no heater wires etc. The simplest
setup is a single wire, which is the signal wire and the sensor get's it's ground from the exhaust pipe.

You can use the following procedure to narrow down which wire is which:
  1. Stick straight pins into the sensor's wires and measure them to ground with the engine running. One of these will show 12 volts, and this will be power for the heater. 
  2. Next find any wires that produce 0 volts. These will be ground wires.
  3. The remaining wire should be your signal wire.Measure the signal wire to ground with the engine running. The voltage on this wire will vary from nearly 0 to about 1 volt. Since your meter will not be fast enough to see the lows and highs, it will average them out to about .2 to about .8 volts. The fluctuations will be so fast you have a hard time reading the numbers. Note, that you have to let the engine warm up a bit before you will get these voltages from the sensor. 

NOTE: The engine must be at operating temperature to perform this check. Many 02 sensors do not
produce a signal until the sensor is warmed to 600 F. If you can not find a signal wire with fluctuations
between 0-1 volt, there is a possibility that you have Wideband 02 sensors. 

If It Is A Wideband Sensor:

If your sensor is a wideband sensor, there will be TWO SIGNAL WIRES - these are called the "Current Pump" wires. The voltages on these current pump wires varies from manufacturer to manufacturer. Toyotas have 3.0 volts on their reference wire and the 3.3 volts on the current return wire. Note that the 3.3 volts will vary slightly as the current flows, but these changes are very tiny.

Nissans use 2.7 volts on their reference wire, and the current wire is approximately 3.0 volts. So far, in all of the 4-wire wide band sensors we've seen, the difference between the 2 current pump wires has been a nominal .300 (300 millivolts), that fluctuates slightly based on current flow.

HINT: When testing- wire that has the higher voltage of the two (Toyotas would use the 3.3 volt wire).
That is the one you will hook up to the EFIE, so save yourself time and mark it now.

For 5 and 6 wire O2 Sensors, you still want to find the TWO CURRENT PUMP wires as above.

Final Notes:

CAUTION! If you find a sensor that uses voltages that are much higher or lower
than those described above, you may have a misidentified wire or device.

In some cars, the ECU "Pulses" the heater wire of the O2 sensor. Your meter may read 6-8 volts instead
of the 12 volts +, because it can't read it fast enough. Do not mistake it for the signal wire or it won't work.

Note:2 Some Chrysler products will produce fluctuations between 2.5 to 3.5 volts. This is only
present in a few Chrysler/Dodge/Plymouth & Jeep models.

Note:3 Some Jeep models from the 90's and very early 2000 models had Titania sensors. We, nor
anyone I know of makes a device for this type of sensor. We suggest checking your manual to see if
this is the case with yours.

If you do these procedures you will guarantee you have found the correct wires and will be able control
the important O2 sensors when using HHO generators.