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O2 sensor hack


Genie47
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OK I found this on eBay:

 

http://cgi.ebay.com/ebaymotors/20HP-O2SENS...1QQcmdZViewItem

 

It basically tricks the ECU to thinking that the engine is running fuel poor and hence blast in more fuel through the injection cycle. I think it can be hacked in a way to make it believe it is running fuel rich as well therefore causing the ECU to lean things out. Air intake volume is still the same.

 

Ingenious or scam? I know if it runs too rich, you basically get the IATS hack situation with blacken spark plugs. Too lean, you gonna see things blow like a hole in the piston. laugh.gif

 

Comments?

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There's no information on how much it modifies the voltage signals to the ECU. Basically we've just trusting them that the modifications are correct and will not screw up your engine?

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err... let me try to understand how this thing works.. [sweatdrop]

it modifies the voltage signal from the O2 sensor, telling the ecu that the engine is running 'fuel-poor' or lean (not enough fuel)... so the ecu sends the signal to the injectors to tell them to spit more fuel inside.

 

but unless the amount of air going in increases proportionally to maintain stioch or slightly lean ratio, then shdn't the engine run richer and just be wasting fuel? assuming that a stock engine is already set to slightly on the rich side....

 

maybe it's only for forced induction cars...? [hur]

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Which is why I think Genie mentioned that there might be a way to hack it to give the signals for fuel lean instead of fuel rich.

 

Personally I don't think the device is going to work, although since it is able to directly modify the ECU's signals, which means that it actually avoids the close loop ECU negation effect, what the device claims to do, like you said, is to increase the amount of fuel while keeping the amount of air constant. That in itself suggests a contradiction to their claim of increased HP (even disregarding the FC).

 

Of course if what they actually meant was to make the engine run fuel lean (not rich), or assuming that there really is a way to make it give signals for a leaner mixture, then it might work, but that brings me back to the first problem I mentioned - just how much are they modifying the values? An overlean mixture will certainly damage the engine. The installer/user has no control over what the device is doing. In essence, you wouldn't know if the device basically causes the ECU to reduces fuel input drastically and thus blow your pistons.

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maybe since most stock engines are set to slightly rich, they use a universal value derived from the averages of most engines? just enough to make significant gain, but still within the safety limits of every engine...?

 

just a thought.. [sweatdrop]

 

maybe u can install a AF ratio meter, tapped just before the 'chip'.. then will know the real condition of the engine

Edited by Yc86
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I don't know.. might be.. but theoretically I think that's quite a scary generalization... cos no engine is made equal, no matter how precise the engineering is. So my feeling is that there is no definition of what is the most conservative change that you can make that will guarantee no failure. But of course it might be possible to make it relatively safe...

 

But anyway the key problem I have is still the point that they are making the fuel mixture richer by telling the ECU that it is running lean. That basically:

 

1. Guarantees worse FC

2. May not allow your engine to completely combust the added fuel causing emission problems and spark plug issues (regardless what they say otherwise)

 

And, just for interest, if you check out their website at www.magnumtuning.com, they are selling the same thing for about twice the price :p The direct link is for the product itself is here.

Edited by Eching21
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Ah! That is where sleuthing in eBay helps! wink.gif I've checked the feedback to this seller. OK dunno real or not but there is this guy with a Subaru Impreza WRX version. He commented that the sensor hack made his car run a little too lean and hence not so good especially for a turbo car. Turbo car need somewhat richer mixtures to be on the safe side to prevent detonation.

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You do get increased HP but the law of diminishing returns takes place. You can burn rich. More fuel indeed makes more horsepower but the horsepower increase only increases to the point till there is not enough air left to make anymore (air limiting). Ditto with the leaning out. You can lean out and the fuel burns completely well producing more horsepower but you lean out too much, get reduced horsepower (fuel now is limiting) and then there is also the mandatory hole in the piston effect. laugh.gif

 

I checked the website. I'm not sure if there are different sensors for different cars or is it just a front to assure you that you are getting a part uniquely designed for your car. You have to select the car you drive for them to ship the "correct hack" to you.

 

Interesting way to do all this snake-oilism besides the air bleeders we see so commonly here. tongue.gif

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The website did say that using an emission meter does help in the tuning but it is not needed. dizzy.gif Another way to "assure"?

 

Interestingly, it will be good to investigate if we can get 2 test cars of different makes to see if the hack supplied is universal or tailored. We would need emissions testers (Yeobh selling Gunson one). Then there is the all important dyno to check it out. sly.gif

 

Wow! If I can get all these tools, we can start out snake-oilism research. laugh.gif

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Actually i think in theory the Powerchip performance module (not the one on eBay) seems workable, and it won't suffer from the ECU compensation effect in closed loop, cos it messes with what the ECU knows, rather than try to modify the values the ECU produces to the engine (ignoring the technical details).

 

Only problem then would be that there is no fine-grained control, cos you essentially "tune" your car using a bunch of dip switches tongue.gif

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Using an emissions meter to help with tuning? Hmm... How do you tune when the product cannot be adjusted? tongue.gif Isn't it just plug it in and cross your fingers? laugh.gif

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You need a five gas emission analyser to do the work. The analyser probe will have to be placed into the exhaust system before the cat to get the actual combustion gase readings From the five gases you can interpret whether the engine combustion is lead or rich etc. The five gases are CO , CO2, NOX, O2, HC. If you take the reading after the cat you can determine whenever your cat is sleeping or working

Edited by Yeobh
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