Changing Wide Open Throttle Air Fuel Ratio
- Location: Engine->Fuel Control (Power Enrich
- Make very small changes and use the scan tool to verify your
- Do not rely on stock O2 sensors for accurate readings, use a
wide band O2 for accurate results.
- Modifying the vehicles air/fuel mixture can result in damage if
not done properly.
- MODIFY AT YOUR OWN RISK!
Air Fuel Ratio Units of measure
- Stoichiometric Air Fuel Ratio: This is the Air to Fuel
mixture considered chemically balanced within the vehicle's
combustion chamber. This number can move up or down dependant upon
the type of fuel being used and what the ideal mixture is
considered. Catalytic converters are designed to be most efficient
when a clean combustion process has taken place prior to passing
through it. This value is used as the base to most other fueling
calculations such as Open Loop and Power Enrichment so changing the
stoichiometric table is not advised in most cases.
- EQ Ratio:
Converting AFR Units of measure
- EQ Ratio to Lambda: Lambda=1/EQ Ratio
- Lambda to EQ Ratio: EQ Ratio=1/Lambda
- EQ Ratio to AFR: AFR=Stoichiometric/EQ Ratio
Modes the pcm can enter that affect your Air Fuel Ratio
- MAF Closed Loop: MAF is Active, Main fueling O2 sensors
- MAF Open Loop: MAF is Active, Main fueling O2 sensors
are Inactive or removed
- Speed Density Closed Loop: Maf is inactive, removed or
Failed, Main fueling O2 sensors are Active
- Speed Density Open Loop(OLSD): Maf is inactive, removed
or Failed, Main fueling O2 sensors are Inactive
||Stoich AFR by weight