O2 sensors for air & fuel mixtures?

[6 packin]

I was going to set this up in my car for tuning purposes. With one O2 in each header pipe or at least as closes as one could get to the head for accurate reading. Some have one, three, and four wires. I belive the black one is the output voltage??? And running them both too 1 DVM (digital volt meter) With a 2 way switch to read the voltages while driving. 2 volt meters are the way to go but i figure 1 will work too. Just use a friend to monitor them while your driving. I done some digging through some old mags and looked on the web here is what I have found.

Readings will be in mV

Too lean - under 250 mV
Good cruise mix- 250-425 mV
(14-15:1) Air fuel, Idea power 425-575 mV
Rich Good for Top end 575-800mV
Over 800 mV Too rich

Just wondering who has done this and what there out come was. Sounds like it would make tunong a breeze!

[JVMopar]

The 4 wire O2 sensors are heated. They have a heating element in them to get them to operating temperature faster. This puts the computer into closed loop and attributes to better gas mileage.

I think you are right about the black wire. You could use a one wire O2 sensor from a brand x car to make it simpler.

[MitchB]

Conventional oxygen sensors can only be used to accurately measure air/fuel ratios closely around stoichiometric or ~ 14.7:1. Their accuracy decays rapidly on either side of this A/F. So if you want to know when you are at 14.7, then you will be O.K. But if you think you can accurately determine your A/F at any other ratio, you can not.

Mitch

[JVMopar]

MitchB-

very true, they make wide band O2 sensors but they are in the $1000's of dollars. Using a conventinal O2 will give you a pretty decient guestimate though.

[timty2]

Hi 6 packin,

If you really desire that kind of resolution, your best bet would be to incorporate exhaust gas temp. Thus, based on temp, you can not only tell how lean or rich you are (High temp vs lower temp) you can use the measuremetns over a wide range of RPM condidtions.

I've seen a lot of high-tech race systems that incorporate this system on each exhaust port, you know, in case you need to know which cyl. is rich or lean!

[Doug Wilson]

Right on, timty2!! EGT is the best, cheapest approach. I once put an EGT sensor about 6 inches downstream of the exhuast port and ran the leads through an 8 position rotary switch, then to an EGT guage. It worked great, but cost a lot.

[cuda66273]

Mitch is right on...I checked into a O2 system that can measure accuratly from about 12.5 to 15.5 and it was about $4000.00...maybe some day...of course if everybody here sent me $1 I'd have one...come on guy's send in your $$$ I accept Visa M/C and cash..please no personal checks

[Doug Wilson]

What.... don't you trust the Moparchat guys, Don????????

[cuda66273]

Not when it comes to real money...a bucks a buck...

Good to see you back on line Doug

Got an email from Dave today....thats a smart boy you have there!

[cuda66273]

I guess everyone lost my address.....haven't recieved any dollar bills yet??

[ajmopar]

I was about to send the envelope full of twenties (U.S. about $5) but my wife smelled the money and intercepted it. Sorry dude.

[cuda66273]

Dam Whimmin....stealing my cash for stupid stuff like grocery's and mortgage payments...they need to get their priority's straight.