Has anybody else stuck an air/fuel gauge in their evo? I spliced into the correct wire on the ecu...mark at turbotrix said it was right. Only thing is...it bounces from lean to rich to lean to rich and doesn't stop. What's wrong with it?

 

i think thats normal, i don't have a gauge but i see everyone elses do that. i think it only matters when you are running WOT if it is consistant lean/rich. also, getting a wideband o-senser helps.

 

That shouldn't be normal. All the other cars I've seen the gauge in...it tells you if you're running lean or rich at any time, not just WOT.

 

anybody?

 

You might need to grab a different grounding spot. Be sure to grab the sensors ground so they have the same source. Give it a shot.

 

I'll try it and see what happens, thanks!

 

If it does it only of start up it could be the ecu, doing its preheat on the cat which can take upwards of 3-5 minutes depending on the current outside tempurature. Also with splicing, what kind of gauge are you using , and which 02 sensor did you splice into?

 

its normal dude, that is the ECU evening out your a/f ratio to try to get a stoich mixture of 14.7 while in closed loop, when you running WOT and you go into open loop then you will see a constant a/f color. Calm down, its fine.

 

No this is not correct..

First, the narrowband O2 sensor is not accurate, and at idle and part throttle driving (Closed loop fuel control) the fuel mixture swings back and forth between rich and lean.. what your seeing is the O2 sensor's reading and the ECU's response.. The only time you'll see a narrowband O2's AFR hover at a particular level is during open loop operation.

The AFR value and voltage response in a narrow band O2 sensor is not linear, but there are only a few 10ths of a volt that are useful in tuning if you can even consider a narrowband useful in tuning (its really not) .80-1.00v's is the useful range, unt in 10ths of a volt, you can see its not very accurate. Plus the refresh rate of the sensor is fairly slow.

In all, do not rely on a narrowband (stock) O2 sensor for tuning since their rarely accurate or consistent for anything other than keeping the car idling or part throttle driving in closed loop.. Those AFR gauges that use the stock O2 sensor are mainly for show and aren't very useful anyway.

 

So you're saying I should just take it back and get something like an EGT gauge?

 

I think an EGT gauge though more expensive, is a more worthwhile use of that space the AFR gauge is using.. Until you can afford or have the patience to install a true Wideband O2 sensor and gauge.

 

Or I can just leave the a/f gauge hooked up to the power and ground without the o2 wire hooked up...it just stays on rich all the time! I'M RICH BIOTCH!!!!!!

 

Jack, does anyone make a cheap(er) wideband o2? Where the output is a gauge? I've seen the AEM one, but it's still slightly too pricey at the moment.


Sorry to hijack the thread, feel free to just PM me back.

 

www.zeitronix.com

 

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