O2 Sensor location

1984 Bronco XLT 351W 4V H.O.

I'd like to wire up an air-fuel ratio gauge. To do that, I need to find the O2 sensor location to read the signal. I have 12v key-on fused source and ground connections.

This truck uses Duraspark Ignition control module with blue tab. I've checked the manifolds and down pipes but none are installed.

This truck has stock emissions including air pump and bpv. Not sure if an O2 sensor is in with that or not.

Can someone please fill me in on the easiest way to connect the gauge. It is the HOTSYSTEM New Auto Car 2" 52mm Digital Color Analog LED Air/Fuel Ratio Monitor Gauge.

Thank you.

That configuration did not have an O2 sensor.  If you want to add one for your gauge you will have to weld in a **** https://www.napaonline.com/p/BK_3353686

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Yo

As Fred advised!

Location Diagram & Depiction in 87-91 at passenger side exhause pipe (from Factory Manual and the Ford Electrical & Vacuum Troubleshooting Manual (EVTM)

Source: by Broncobill78 (Dave) at http://web.archive.org/web/20110915014807/http://broncozone.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=6665

...

"...Autometer Air / Fuel Ratio Monitor Wide Band Pro #4375

The heated oxygen sensor comes with a stainless steel weld-in ***** plug, and wiring harness with a weather pack connector. The oxygen sensor should be installed as close to the cylinder head as is reasonably possible so that the sensor reaches operating temperature quickly. If long tube headers are used, the oxygen sensor should be installed in the collector. If cast iron manifold(s) or shorty headers are used, install

the sensor in the pipe just below the manifold. In multi-bank applications mounting in the left or right side is acceptable. Turbocharged applications should have sensor installed 4-5" after turbo on the down pipe.

The Air / Fuel Ratio Monitor can be used with the following fuels.

NOTE: OK for use with Nitrous Oxide.

NOTE: Stoichiometric Air / Fuel Ratio is the chemically correct

ratio where theoretically all of the oxygen and all of the

fuel are consumed. The mixture is neither rich or lean.

Mounting Sensor

Auto Meter recommends welding supplied stainless steel **** with a TIG welder.

Fuels

Unleaded Gasoline

Methanol

Ethanol

LPG (Propane)

CNG

Stoichiometric Air / Fuel Ratio

14.7:1

6.4:1

9.0:1

15.5:1

17.2:1

Operation Guide

This product has many features that can be adjusted for your specific application. Use the MODE (-) and SELECT (+) buttons to navigate menu options, confirm selections, and fine tune options to your needs.

Acronyms:

A list of acronyms and abbreviations are defined below in order to help you more clearly understand the menu operations, functions, and components available on your Auto Meter Wideband Air/Fuel gauge:

BGD – Bar Graph Display. This is the curved, multi-color, LED radial display used to indicate how “Rich” or “Lean” the current Air Fuel or Lambda reading is relative to your Stoichiometric point with respect to your upper and lower range tolerances.

SSD – Seven Segment Display. This is the digital numeric display that indicates your current Air Fuel or Lambda reading. This display is also used to help you navigate and make changes to your settings.

AFR – Air / Fuel Ratio. This is shown as a numeric value on the SSD, characterized by only having a single decimal place (i.e. 14.7). This value is also visually represented on the BGD, indicating whether the value is “Rich” or “Lean” of the selected Stoiciometric value and relative to the upper and lower range tolerances. AFR, as the name implies, represents the ratio of Air to Fuel being mixed and consumed, in real time, by the engine / vehicle upon which this instrument has been installed.

ʎ Lamda, is an alternate way of expressing AFR, assuming that the stoichiometric point selected equals one and readings “rich” or “lean” will be expressed as values above or below one, characterized by a value displayed with two decimal places, (i.e. 1.00). The gauge can display data in either AFR or Lambda as needed by the user.

1. The exhaust pipe in front of the sensor should not contain any pockets, projections, protrusions, edges, flex-tubes etc. to avoid accumulation of condensation. A downwards slope of the pipe is recommended. If the exhaust pipe is parallel to the ground, the sensor must be installed in the top half of the pipe to avoid damage to due to condensation

2. Tightening torque: 30-44 ft Ibs.

3. Avoid excessive heating of the sensor cable. Route sensor cable away from exhaust pipe.

4. The maximum temperature of the sensor on the outside of the exhaust fitting should not exceed 900o F.

...

If your vehicle is not originally equipped with an oxygen sensor, purchase Auto Meter model number 2244. The heated oxygen

sensor comes with a weld in boss, boss plug, and wiring harness

with a weather pack connector. The oxygen sensor should be

installed in a spot where exhaust from all cylinders flows past

it. The oxygen sensor should also be installed as close to the

cylinder head as reasonably possible so that the sensor reaches

operating temperature quickly. If headers are used, the oxygen

sensor should be installed in the collector. If cast iron manifold(s) are used, install the sensor in the pipe just below the manifold.

Mounting in the left or right side is acceptable. If monitoring of both sides is desired, a second oxygen sensor can be used and

a switch (purchased locally).

Fouling and/or permanent damage to the oxygen sensor over time will result if used with any of the following:

• Leaded gasoline and fuel additives containing lead

• 2 cycle gasoline (gas/oil mix)

• Diesel Fuel

• Nitromethane

• Excessively rich mixtures

If the Air/Fuel Ratio Monitor responds sluggish, the oxygen sensor is probably partially fouled and should be replaced.

Do not connect ohm meter to oxygen sensor, or touch wire to ground or power. Damage to oxygen sensor will result. If a volt meter is to be used, only use a high impedance (10 mega ohm or higher) digital multimeter..."

Read more @ http://www.autometer.com/resources/index/instructional

Thank you... I didn't believe there were any o2 sensors and needed verification. I replaced my exhaust manifolds when I did a complete rebuild. The driver side manifold has a **** on each cylinder with a plug installed.

I was wondering if the o2 sensor would work properly installed in the last one before the exhaust goes down the side pipe?

Thank you for sharing your knowledge,

David

Yo David,

"The oxygen sensor should be installed as close to the cylinder head as is reasonably possible so that the sensor reaches operating temperature quickly."

So, yes, install it where that plug is located. All Broncos had the sensor in the y tubes, closer to the exhaust manifold than the catalytic converter.

Great, that's what I will do. I ordered the o2 sensor from rockauto.

Thank you Miesk5

The plugs at each cylinder are not for O2 sensors, they are for air pipes.  The **** goes on the exhaust pipe after the Y and before the Cat so that you get a reading on all cylinders or you can get this passenger side manifold with an O2 hole.  http://shop.broncograveyard.com/Exhaust-Manifold-351W-Right-W_-O2-hole-80-87/productinfo/30008/

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Yo Fred,

Thanks!!!