Hey guys I am looking to lean out my n/a a bit more and while im still gathering funds for a dyno/wideband session I am interested in rough tuning it myself. I read on here that you can hook a voltmeter up to the 02 sensor and then according tot he readout tell when the mixture is stoichiometric. Can anyone tell me what guidelines to go by when doing this such as what readout is stoich, rich, lean. Before anyone gets scared im not taking this too seriosuly, I know nothing can replace a wideband. I am just curious about this method.

 

spend the 250 dollars on the real deal. get a wideband and thats that. the stock o2 sensor is a narrowband meaning, it only reads accuratly at stoich. which is useless. period.its like if god made women blurry all over and suddenly they could bee seen clearly in the vagina. not good. you wanna see everything. from one end to the other end.

women, dont take what i said seriously

 

are you saying that the O2 sensor is the reproductive organ of rx-7s? just kidding, but i was curious, how does the O2 sensor with the voltometer work for tuning, regardless of how little of the spectrum it covers?

 

It doesn't.

 

It would be the equivalant of a narrow band 02 gauge but without the cost.

It'll read b/t 0 and 1 vdc. Stoic will show rapid changes b/t 0.4 and 0.5 vdc (memory here). Rich will be any thing over something like 0.7 or so. Lean would be low figures like 0.3vdc or 0.000 or anywhere inbetween.

That's from memory. I don't care right now to backprobe pin 2D with a meter.

If a airpump is installed AND the ACV is working right, you'll consistantly read 0.000 vdc at idle due to the airpump air being dumped into the exaust ports which are before the 02 sensor itself.

Go for a ride and stomp the pedal and the ACV won't be dumping air into the exaust ports anymore if its working right, and the figure will go into the 0.8 vdc range, which is normal.

Anyway, that's some things you should more or less see using a digital meter. At least it'll give you an idea of what is happening.

 

For hardcore tuning it doesn't. But for finding out if you're close it's no differnent than using a Narrowband A/F gauge.

Or buy the wideband sensor and use the multimeter to read that voltage. Instead of being 0v to 1v, it'll be 0v to 5v.

 

That's not true at all. Using only a narrowband, this summer I tuned the vacuum ranges and low boost ranges on my car. I just recently pulled my O2 sensor in preparation for installation of the big turbo and found that the sensor element and inside of the pipe were a perfect dark tan colour. So I'd say that's a pretty good A/F ratio for something that can't be done.

You just need to know the characterists of the stock O2 sensor and it's ranges to do this.