02 sensors and tuning

[salty21]

Looking at getting a new exhaust for my ninja (p8f). It has an 02 sensor/lambda sensor located just before the catalytic converter. will this adjust the fueling automatically to a safe level if i gut the cat and stick a race can on it, or will i need to get a power commander for it to make it safe.

I'm not really bothered about having the fuelling spot on as both my old rr and sp had very snatchy injection systems so i'm kind of used to it and it never really bothered me so id rather save the £270 a power commander cost if i can. All i want to know is will the lambda sensor automatically adjust the fuelling to the point where it wont do any harm?
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04 NSR 125(sold) ---- 03 CBR 600rr(sold) ----90 pan euro ST1100 '' ----02 CG 125
94 CB400 Super Four ---- 2000 VTR SP1 (sold) ---- 08 ninja p8f(sold, meh) ----05 CBR600rr

[0ddball]

Unless it's a wideband sensor it will only affect the fueling when running in closed loop, i.e at steady throttle. The real danger is under load at full throttle which is when it's running open loop. Then it is looking up fueling from a pre programmed map and ignoring the O2 sensor.

Only way to be sure is to fit the exhaust then do a dyno run.
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ZXR750L

[Wafer_Thin_Ham]

They can only adjust the fueling within a very narrow range. So with a race can it wouldn't automatically adjust the fuelling by a large enough amount.

A PCIII's the way to go anyway purely for more power and more fuel economy.
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My Flickr

[salty21]

cheers guys. PCIII it is then, i'll just keep my eyes peeled on egay for a second hand one i think.

On the bright side im about to lose a good chunk of weight off the bike by removing standard can, cat converter, servo valve system and whatever else i find related to emmisions control.

How good are the downloadable maps? Its obviously going to be better to get a custom map done but this is going to cost me a small fortune already
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04 NSR 125(sold) ---- 03 CBR 600rr(sold) ----90 pan euro ST1100 '' ----02 CG 125
94 CB400 Super Four ---- 2000 VTR SP1 (sold) ---- 08 ninja p8f(sold, meh) ----05 CBR600rr

[Wafer_Thin_Ham]

The downloadable maps are an ok starting point, especially if you can get a UK one with the same mods as your bike.
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My Flickr