Stack LAMBDA Guide D'installation page 2

Mounting Sensor
The included Bosch LSU4.9 heated oxygen sensor comes with a stainless steel weld-in bung, plug (in the event the module is not being used and
the sensor has been removed), and wiring harness with a weather pack connector. The oxygen sensor should be installed on the exhaust manifold
as close to the cylinder head as is reasonably possible so that the sensor reaches operating temperature quickly while not exceeding the maximum
hexagon temperature of 1,112ºF (600ºC) and maximum exhaust gas exposure temperature of 1,706 ºF (930º C).
If long tube headers are used, the oxygen sensor should typically be installed in the collector for applications where individual cylinder readings are
not required. If cast iron manifold(s) or shorty headers are used, install the sensor in the pipe just below the manifold seeking an ideal distance of 18
in. (46 cm) from cylinder head exhaust port or turbo exhaust port. In multi-bank applications where a single sensor is being utilized mounting in the left
or right side is acceptable and should ideally place the sensor on the bank known to house the leanest cylinder. Open header applications will require
a minimum length of 18-24 in. (46-61 cm) of exhaust pipe after sensor for proper reading at idle and part throttle.
Sensor Tightening Torque – 33 – 44 ft. / lbs.
Route sensor cable away from sources of heat (such as exhaust pipe) and RF / EMI such as charging system, fuel pump, and ignition wiring.
IMPORTANT!
- Auto Meter recommends welding supplied stainless steel bung with a TIG welder.
- Sensor bung should be welded at an angle that places the sensor a minimum of 10 degrees above horizontal (paralled to the ground) to
allow for condensation drain and less than 90 degrees from horizontal to avoid overheating the sensor.
- Exhaust pipe in front of the sensor should not contain any pockets, projections, protrusions, edges, flex-tubes, etc. in order to avoid
accumulation of condensation which can damage the sensor.
- Open and/or leaky exhausts and camshaft overlap are known causes of false lean sensor readings at light to moderate engine loads.
Once engine load increases and increased exhaust volume is present reading accuracy improves as fresh air spoiling the readings is
expelled from the sensor element.
- Always install the sensor prior to any Catalytic Converters present on the vehicle's exhaust to ensure proper readings as the catalytic
converter will cause readings which are leaner than actual, the amount of variance is affected by engine load and efficiency of the
converter.
- Sensor will got very hot during operation – exercise appropriate caution when working near to the sensor to avoid burns and locate
accordingly to avoid damage to nearby vehicle components which may be heat sensitive.
- This sensor is considered a wear / consumable part (which is not covered under warranty) with manycontributing factors that make it
impossible to predict longevity for all applications – plan spares accordingly.
- Leaded fuels, Nitromethane, two stroke mix (oil), engine coolant (blown head gaskets), particulates / carbon (excessively rich mixtures),
sensor shock (impact or drops), and exceeding safe operating temperatures (excessively lean conditions) are specifically known to
reduce overall sensor life.
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 STACK Wideband Air/Fuel gauge:
BGD – Bar Graph Display. This is the curved, multi-colour, 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.
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.
Real-Time Mode:
Real-Time mode is the default mode of operation for this product. When Real-Time mode is active, the instrument will display the current
air/fuel ratio in either AFR or Lambda.
To toggle between AFR and Lambda display types, press the SELECT(+) button. Remember that AFR values have a single decimal place
(i.e. 14.7), and that Lambda values have two decimal places (i.e. 1.00).