ok i got a question about my o2 sensor

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Apr 13, 2009 | 04:43 AM

#21

aen

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Joined: Aug 2006

Posts: 5,750

From: Las Vegas!

im not even turboed man, i'm bone stock now, havn't you been paying attention? haha

Apr 13, 2009 | 05:05 AM

#22

CarbonXe

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teamNJCT
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From: Parsippany, NJ

rofl obviously not hahaha.

Apr 14, 2009 | 01:04 AM

#23

alltracman78

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Joined: Apr 2009

Posts: 37

Quote:

Originally Posted by aen

i speak in layman's terms so people will understand whats going on....and so not to confuse them with this technician mumbo jumbo.

I am a tech; in fact I'm a master tech, the mumbo jumbo is fine with me.

Quote:

Originally Posted by aen

it takes the amount of o2 in the exhaust and compares it to the amount of oxygen in the atmosphere, hence 14 parts per million in exhaust to 7 parts per million in atmosphere

It does compare the amount of oxygen in the exhaust to the amount in the atmosphere; however you have the amounts wrong.
The earths atmosphere is roughly 20% oxygen, which is quite a bit more than 7 parts per million [that is 0.007 % I believe]. And the amount of oxygen in the exhaust gas is not a set amount, it changes, hence the need to monitor it with the oxygen/A:F sensors. Like I've already said, it checks the amount of oxygen in the exhaust [not the amount in the atmosphere, that stays basically the same] and the ECU uses that to help adjusts fuel trims.

It sounds like you're somehow confusing stoichiometric air:fuel [14.7 parts air to 1 part fuel] with this.

Quote:

Originally Posted by aen

it dumps fuel according to the readings it gets from the MAF sensor, the crank sensor and the cam sensor it all reads those and compiles data and sets the fuel trims to what math says is the amount of fuel that should be dumped into the intake.

would you like hte formula too?

It definitely adds extra fuel when it has no reading from the A:F sensor, however all it does is go to open loop operation, meaning it only uses the fuel maps, it doesn't adjust for the A:F sensor input.
"Dump" is an arbitrary word [there's no set meaning] so I can't tell you it doesn't "dump" fuel, because it does use more fuel.
However it definitely does not pour massive amounts of fuel into the engine, it uses no more [it actually uses less] than if it was at WOT. Which considering it's an NA engine isn't all that much. I doubt the A:F is even down to 12:1. Turbo cars run richer than this stock [at WOT and under boost].

I would certainly be interested to see the formula; can you post it up?