I have map AND maf...now what?

[hg2]

Dustin make sure to check your voltage of the 2 pre cats upstream from the one before the cat.I've not familar with that set up with 3 O2s.I'm unsure if you need to address those 2 or not they may just be egt sensors.I can ask over at another forum that deals with O2s quite a bit bit and get you an answer,might take a day or so.Or ask Jaxom if he knows,he's well versed on sensors and may be able to help you.

[Keith's Garage]

The maximum O2s you would have to mess with would be two. Each bank has only one pre cat oxygen sensor (upstream). every other sensor is like Hg2 said, an egt sensor or post cat.

[Jaxom]

I am just curious as to what you believe is the best way to have the computer lean out the motor?

Teach the computer to use the HHO instead of fighting it.

Unfortunately that's a lot easier said than done. Simply changing the fuel and spark curves programmed into the PCM will help, but won't fix the problem. In closed loop, the O2 will still fight any sensor/programming changes you make, because it will always strive for a 14.7:1 air/fuel ratio. If you can figure out how to force your PCM to stay in open loop, the O2 readings are disregarded and the PCM runs strictly off the programmed calibration. That's the short term fix. The long term fix is a fundamental reprogramming of the computer's fuel trim feedback calculations to accouont for HHO and it's effect on the O2 readings, which is way beyond what 98% of people can do. The manufacturers may eventually address this, but unless you're an automotive engineer who's good with computer programming and youo have access to the source code for your vehicle's PCM programming, you just can't do it yourself.

As it happens I do have a reverse-engineered copy of the code for my IROC-Z. You can find stuff on the 'net if you get pretty deep into the performance tuning community. The code for my 20-year-old car is over 300 pages in print form, and things have only gotten more complex since.

[Jaxom]

Also, I agree with Keith on the O2's. The ones nearest the engine on each side are the feedback sensors, the others are for emissions diagnostics.

[Keith's Garage]

Jaxom, I completely agree with you on teaching the ECU to use the HHO. I just dont see that happening unless the manufacturers do it. The complexity of the newer vehicles is way to much for most people. For right now, I feel we need to "trick" the computer, though try to still leave as much control as we can to the computer.

[H2OPWR]

Man, you guys are awsome. The more I've read, I do believe I will concentrate on the O2 sensors. Seems like it may be slower but yield more solid returns on fuel economy.

I'm really into building my own stuff. I get frustrated buying things like O2 enhancers, taking them apart, and seeing I could have bought the stuff at Radio Shack for a few dollars and put out a little effort to build it myself. I went to Radio Shack today with an idea of how to introduce a few millivolts to the O2 signal to the ECM. After talking with the owner he determined that I needed a certain trim pot I think it was. I came back to the garage and wired it as the schematic described on the back of the package. I applied 12 volts to it and adjusted it down to .200 volts output. Now, can I introduce that .200 volts which is what I'm just guessing as a starting point, I can adjust it with very high accuracy anywhere from 0 volts to battery voltage to the signal wire from the O2 sensor to the ECM. I'm thinking (hoping!) I can simply build a box that has 12 volts to it running through the pot adjuster and send the adjusted .200 volts to the 3 pre-cat O2 sensors......1 from the left bank, 1 from the right bank, and 1 just before the catalitic converter. There is one after the converter but I've read that just checks its work. Since I will be running one adjuster, all the sensors will be receiving the same skewed signal hopefully convincing the ECM that things are "normal" and to look elsewhere for something to do.
I'm kinda concerned that the voltage I'm sending might backfeed into the O2 sensor but I don't think it will do anything but stop right there.

Am I on the right track or on the verge of costing myself alot of cussing and money?!

Dustin, I thind the Idea you have described might just work but make sure that you put a diode (one way check valve for electricity) in the circut. If you put one in the added voltage can not feed back to the 02

[Boltazar]

I also agree that we should be able to reprogram our computers to use HHO ..........BUT..........what happens when the HHO generator fails, the engine stops. It would be nice to be able to switch back to stock programing on the fly

[Dustin]

I had given the diode idea a thought but wasn't sure if the voltage would just end at the sensor or meet the reference voltage and stop there. I guess the diode wouldn't hurt anything would it? They don't have a voltage drop of any kind do they? What about when the signal voltage from the O2 sensor goes above my .200 volts I'm feeding into the signal wire? Wouldn't it force it's way back to the pot adjuster totally erasing what I'm trying to accomplish? I think I'm only going to be raising the bottom side of the voltage "swing" with my .200 volts. Anything higher from the O2 sensor than MY voltage is going to be erased......I think. Voltage is pressure. Higher pressure wins everytime.

I think there needs to be a way to "amplify" a given voltage. I'm absoutely no electronics person by any means but I do somewhat understand how DC voltage flows and behaves. If a voltage signal was rerouted to something that could amplify voltage by a couple of millivolts, I think it would be more consistant and believable by the ECM.

Again, I'm just getting started in this stuff and maybe way off track. I will say that JAXOM is right with the idea that a whole new program needs to be written for hydrogen. I wonder if a company like Hypertech or Diablo knows of such a possible need?

[Dustin]

I thought of something today. Instead of modifying the signal back to the ECM from the O2 sensor, what would happen if you modified the reference voltage going to the O2 sensor. Isn't the O2 sensor just a variable resistor that reacts with oxygen to vary the signal voltage back to the ECM? If it is just a resistor, then any input change would surely effect the output.....wouldn't it?

[Jaxom]

It's not really a variable resistor, but an actual voltage generator. Nonetheless, raising the reference voltage (a.k.a. sensor ground) to the sensor should raise the output by the same amount. We recently figured out that Dodge does this from the factory with the Hemi trucks.