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Using factory oxygen sensor for A/F ratio measurement

Grim

By Grim,
in Engines & Forced Induction

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Grim Proficient

Grim

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Posted

Is it possible to tap into the signal from the stock oxygen sensor on the front pipe to measure the air fuel ratios and tune the car?

I've seen some aftermarket gauges that apparently use the signal to report if the engine is running lean/rich but they are not reliable at all.

Is the only way to read A/F ratios to use expensive oxygen detectors at the exhaust exit?

Cool Hand Luke Community Regular

Cool Hand Luke

Posted
Posted

No, any aftermarket computer will use a lambda probe (same as the standard) to measure fuel ratios. However if you disconnect your sensor from the ecu and plug it into the guage, then it will become inaccurate because the ecu needs the sensor to make fueling adjustments for part throttle, and wide open throttle. Also unless a guage gives a figure, i dont really see how its accurate... the whole rich/lean thing with a light inbetween would be no where near as accurate as a number reading.

Roy13 Enthusiast

Roy13

Posted
Posted

You carn't use the standard items as they have a response curve centred around 14.7 : 1 were they are designed to work, you can buy a Jaycar kit that turns the output to a digital read out exetra like 12.8, 13.2 but they are only good for a rough idea.

Like mensioned above you need a wide band sensor which cost about $350 and a display to view, like the one link make for $400 expensive but look the part too.

Clint i got the ceramic clutch you sugested it is great!

  • 4 weeks later...

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