Engine power when in default mode

[Dessertrunner]

Matt and I were talking about what would happen if he leaves the O2 sensor disconnected. I was of the opinnion that the ECU would go into default mode and run off standard maps.
Our question is will that reduce the power the engine puts out or not.

[NikFu S.]

I thought someone ran without O2s and found it was faster, but had trouble when they tried to reconnect them?

[ItsPeteReally]

Originally Posted by Dessertrunner

Matt and I were talking about what would happen if he leaves the O2 sensor disconnected. I was of the opinnion that the ECU would go into default mode and run off standard maps.
Our question is will that reduce the power the engine puts out or not.

A one word answer is probably.

A longer answer is that any default mapping has to be safe, that means that it has to be richer than optimum, as weak mixtures can lead to overheating, pre-ignition and engine damage.

So the default fueling maps have to be rich for all engines coming off the production line that lie within normal production tolerances. So for any particular engine, the results could vary somewhat. Add to that the fact that any SVX engine will have tens of thousands of miles of wear by now and the problem becomes even more difficult to analyse.

So the answer remains probably.

The saving grace is that the power output is not particularly sensitive to fuel/air mixture; you might see the difference on a dyno, or the dragstrip, but in normal usage this would go unnoticed apart from a slight worsening in fuel consumption.

[oab_au]

I don't think it will matter, as far as power goes. When the foot is down hard, the TCU doesn't care about the o2 readings. It is reading the full throttle, full power, map.

Harvey.

[Dessertrunner]

THanks guys what you say makes great sense.
Tony