O2 Sensor Voltage To Lean Out
 

I tried posting this in the General forum but got no answer so ill try it here...

I have a 2002 Chevy S10 and I just added an HHO Unit.. I want to add a voltage enhancer to lean out the fuel mixture... Here is my dilemma, a few weeks ago my Check Engine Light came on... After getting it read by autozone they said that both of my pre cat sensors are bad... Now here is my question...

Do I need to replace the O2 Sensors before adding the enhancer or can I just leave them alone and add the enhancer... If I am reading the instructions to the enhancer correctly, by adding the unit I am bypassing the O2 sensor to begin with... Please correct me if I am wrong?

thanks love the site

Dan

the answer is I don't know but I figured I post since no one else is.

I would suspect since your back two oxy sensors aren't working then you are running in open loop which is causing you to run on a pre programmed fuel map which means you are probably running rich. not stupid rich but richer than normal. when I am running normally I am running 14.7:1 and when I go into open loop it hits 12.5:1 for the air fuel ratio.

I figure your gas mileage is probably worse than it could be if they were changed. if it were me (and it's not) I would change them first just to get a good baseline before changing anything. also realize that if you lean out your mixture too much you may damage your engine. that isn't worth a few mpg for a little while.

BTW: I have a 2.2 liter and I know some of the s-10s had them as well.

when you get everything straight, start a gas log, we would love to see your progress.

side note: I am trying to be more positive.

Thanks BEEF for replying.. My S10 is a 4.3L V6, I have a baseline for what my truck was running before the O2 sensors went bad... I was getting 15 MPG before the failure of sensors... That is what my truck runs stock, I have no improvements what so ever... I will probably order new sensors this week as well as the enhancer... I was just thinking about saving some money and putting it towards other addons...

Thanks again BEEF, anyone else?

Dan

I don't have one of these units, but from what I've read they add bias to the oxygen sensor readout, so they do need to be hooked up to the oxygen sensor. The enhancers just fudge the oxygen sensor's signal a little bit to make the engine run leaner. So yes- you do need an operational oxygen sensor for it to work properly.

If you put then enhancer on with no oxygen sensor, either it won't add any bias because it has nothing to work from, or your computer will think that the oxygen sensor is bad and the check engine light will come on and your will be back where you are now.

I doubt that you will hurt anything by adding the enhancer in to the bad oxygen sensors that you have now. If your check engine light goes off afterward then it probably is working.

A bad Lambda or O2 sensor will give a lower voltage so you don't need the extra resistor to lean the fuel out, you need to check the voltage on the O2 sensor to be sure, 5 volts is the norm I think when its fully warmed up.

About 0.45 is normal for a warmed up O2 sensor on an older car. Some newer cars with "wideband" O2 sensors, may be closer to the 5V range.

Does the wide band sensor have some kind of voltage get the voltage higher?

Thanks guys, I just got finished probing my 02 sensor and my car is running at about .85 after warmup... It oscillates between .20 and .85 and is hesitating real bad now... I turned the hho unit on and the idle leveled out... So i think i am going to be ok since it is already running lean and seems to work with the hho unit.. Now to see if my mpg improves... I also have the COSM IIA on standby in case it goes on the rich side... I should have my MAF Enhancer done tonight..

Dream

We anxiously await your detailed findings!!

:D

Hho Info
 

The best place to ask that question would be https://hhoinfo.ning.com

Gabet123

I also want to add that if you set up your engine to run lean, be careful because detonation is very bad for an engine. there is a reason it is set up for the air/fuel ratio that it has. it could probably go leaner but if you go too lean, it could do serious, permanent, and potentially catastrophic damage to your engine.

I am not saying not to experiment but keep that in mind.