I'd like to bounce this idea off some people who know more about engine management than I do.

What if, five or ten minutes before the engine was started, the oxygen sensor heaters were turned on? The car would start up and be in closed-loop mode, rather than running rich for the first few minutes, right?

How long does it take for a heated O2 sensor to get up to operating temperature, anyway?

Would this save a meaningful amount of gas, considering that I drive mostly short trips?

It might be too lean for the engine to run correctly when cold. Fuel isn't atomized very well with a cold engine, so it just takes a bit more for the first few minutes, just like a carb with a choke plate.

It's true that it'll take more gas when cold. However, in closed-loop mode, rather than just making generous guesses as to how much fuel is required, it would compute exactly how much is needed.

What I don't have any idea about is just how much fuel would be saved.

 

Does anyone here have a Fuel-Air Gauge? If so, please tell me how long it takes for your O2 sensor to heat up. If not, I'll have to make a gauge out of a few feet of wire and a voltmeter.

My point was if you fool the sensor into thinking the engine is warm, it probably won't run very well when cold, with the lean mixture it will be getting.

 

I think it might be worth all this trouble if gas was $25 bucks a gallon, but IMO, you should get a hobby!

Heating the O2 sensor does not fool it into thinking the engine is warm. The O2 sensor is more accurate and responds faster when it is hot than when it is cold. That's the reason for the heater. IMHO it shouldn't take even a minute to heat the sensor properly. I wouldn't even bother with pre-heating.