OBD2 Fuel Enrichment Mode

[dkjones96]

Does anybody know where I can find more information about this? I want to know what mixtures it aims for and such or if it is a pre-programmed map.

I know my car will do it under heavy load for more power and to an even greater extent if the engine begins to overheat to keep it cool along with ignition timing retarding but I can't find anywhere that will give further details...

[suspendedhatch]

I haven't heard of anything so much as a "mode"... what you are describing is built into every tune. It's not exclusive to OBD2. You NEED more fuel under many conditions to prevent the engine from blowing up or simply to keep it running smoothly. Cold start, a sudden throttle increase (even just leaving from a stop at a normal pace), to stabilize idle immediately following startup, heavy load or boost, when knock is detected, as a fail safe aka limp mode, when coolant and/or air temps drop too low, when an alternative fuel is detected on a flex fuel vehicle, etc etc. This isn't something you would ever want to tamper with or override, even though some manufacturers may be criticized as being overly cautious.

All I can suggest is that you get a wideband O2 sensor / gauge combination like the one made by AEM. You can leave your stock O2 intact and simply have a bung welded nearby for the additional sensor. Then you can monitor your air fuel ratio and learn to avoid getting into situations that require rich mixtures.

[theholycow]

What about tuning out open loop at WOT? Is it necessary to have open loop and fuel enrichment when at WOT or can one tune it out and accept a power loss without endangering the engine?

[dkjones96]

We should be able to accept the power loss. My car for example goes into its power enrichment mode as low as 75% throttle which is why my exahsut pipe has so much black on it... i'm always running ~75-85% on acceleration.