Is there any extra Oxygen in exhaust

[Johnh]

I've been trying to figure out the differing results from O Sensor mods on different vehicles and have come to a stumbling block in my work.

Was trying to write a formula on what oxygen there is in the exhaust and came to the conclusion there is LESS.

We inject a Stociometric ratio mixture of Hydrogen and Oxygen into the engine, when this recombines it leaves no excess oxygen. In injecting the mixture into the intake we have displaced a small amount of air so have a small amount less oxygen. If the same amount of fuel is injected the mixture should be slightly richer.

Where are the extra O2 readings coming from ?? Or is something else causing wrong O2 readings?
Is this why some sensors detect extra O2 and some don't on the same size engine of different make ?
Is this why there are similar problems with similar ECU's on different engine sizes.?

All suggestions welcomed
John

[midnight cruise]

In injecting the mixture into the intake we have displaced a small amount of air so have a small amount less oxygen. If the same amount of fuel is injected the mixture should be slightly richer.
John

This is true if you are injecting the HHO ahead of the MAF sensor, but if you are injecting it straight into the intake, you are slowing down the air coming across the MAF and the injected HHO is not accounted for in the initial calculation. This is true in "Closed Loop" mode, but all bets are off in open loop mode. Most PCM's dump too much fuel on purpose because the O2 sensor does not become available till it's temp reached 600 deg F.

I am not a fan of messing with the O2 sensor... leaning out an engine does lots of bad things to heads, piston tops, O2 sensors, and cats! HHO does have a cooling effect, but the problem with offsetting the O2 is that offset will only be accurate for a set RPM. Above that set RPM you will be way too lean and below will be rich.

If you want to play with the O2 sensor output, it should be a inversely proportional to the MAF reading (since the HHO is a steady rate). To do it correctly, you should use a flow meter on the HHO and use that signal to offset the MAF and the MAP at the same time.

Back to your questions...
"Where are the extra O2 readings coming from?"
I don't think there is any extra... if you inject directly into the intake and are running "closed loop."

"Or is something else causing wrong O2 readings?"
Might be that some vehicles are using an O2 before and after the cat... they are looking for O2 differences to see how effective the cat is. I'm not sure what introducing steam into this would cause. Might be cooling the cat down too much, so additional fuel is being added?

"Is this why some sensors detect extra O2 and some don't on the same size engine of different make?"
I know Bosch sensors on GM OBDI PCM's typically read too much O2. Every one I have installed (20 or more) has sees fuel economy drop, when the switching from AC Delco to Bosh on GM OBDI PCM's... Bosh is typically 30% lower $ (which is why people buy them). On other vehicles they work fine.

"Is this why there are similar problems with similar ECU's on different engine sizes.?"
Again I think it might have more to do with the MAF and the injection point of the HHO.

Hope this information from my limited experience helps....

[Johnh]

Thanks MC more to chew on
John