That stupid O2 sensor on F4i's
 

So I found a kick ass cheap aftermarket exhaust for my 06 F4i, but the midpipe didn't have the bung for the o2 sensor. I asked the dude on ebay why he would advertise it as an 06 compatible if that O2 sensor doesn't exist, and I got a pretty good answer:

"The system is designed to read the Oxygen sensor under certain conditions and temporarily change the air/fuel ratio. The closed loop circuit has a very limited operating range, which is only in effect while holding a steady speed at certain rpm's and throttle positions. In this limited area, the stock system (with or without the Power Commander) will gradually and temporarily lean out the air fuel ratio in an attempt to achieve an air/fuel ratio of 14.7:1 (stochiometric).
The Oxygen sensors can be disconnected but this will trip the F.I. dash warning light.

If you remove the sensor and bridge it with a suitable resistor the F.I. will always read a correct a/f ratio and does not lean out the fueling in this speed/rpm ranges.

The whole functionality is not used to increase performance or mileage, it's simply to fullfill the homologation requirements"


SOooooooooo If that is a fact (and half the reason for this thread is to see if that actually is a fact) then why aren't these O2 sensor resistors everywhere???

Has anyone of you fellas heard of this.


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You can buy an o2 sensor delete kit from dynojet for like $20. Its just a little thing that plugs into the harness where the sensor goes so the bike stops throwing the fi light. Or you can do it yourself for free/almost free. You dont need the rear o2 sensor and like he said theyre just put on the bikes to meet certain emissions requirements and such. The 01-03 f4i's sold in california all had o2 sensors on them as well since that state has stricter emissions regulations.

Thanks nick. After a long back and forth with the $155 dollar eBay Danmoto exhaust guy I found a sensor restrictor from the UK for like 29 bucks.

Im hoping the dang thing isn't ridiculously hard to put in as I am not McGuyver.

Lets see how this china exhaust and no more O2 sensor work out

I'll keep things updated right here

I was looking at DanMoto exhausts for my '06 F4i the other day and I was planning on getting the slip-on when I got some money.

Do you need to worry about the O2 sensor in that case? I read on their website that it shouldn't matter. :\

I can walk you through the whole O2 thing man... you need to get a little 30 dollar plug that makes the bike think the Air/fuel ration is always correct.... or else the damn bike keeps on lighting the Fi sensor light on the dash... and the spark plugs get fouled up because you are running too rich...

if you add the 30 bucks to the dan moto price, it's still a fraction of the price of gettin a brand name exhaust.

Mine is in the mail... I will put pics and thoughts on here

Run upto the local hardware store and pick up a nut that fits the O2 sensor. Then run to your local exhaust shop and have them weld the nut to your mid pipe. I did that w/ mine and they charged me $10 to weld it on and the nut cost $1.25.

Moses

so I rode the bike with the Fi light on and I don't know if I was hallucinating, but the damn things spins up faster. I think keeping the O2 sensor deadens the acceleration, but I may be wrong.

I hope it still acts like this when I put the delete chip into the wiring harness.

Usually I am at 60 MPH @ 5,000 RPM

yesterday I was at 63 MPH @ 4,800 RPM

....

Go to radio shack and get a 99cent 330 ohm resister unplug o2 sensor and toss aside, push the resister into two of the slots tape up and light goes off and bike runs great. Thats all those $30 plugs are. Check this out DIY $.99 DIY O2 (oxygen) sensor eliminator : Honda CBR 600RR Sportbike Forum : 600RR.Net this works on f4i too but wire color is different. I forgot which two colors the resister goes to but if interested ill take a picture of mine.

The way I see it and it may be an "older you get" kind of thing but the engineers that designed the fuel system spent a ton of time and money allowing it work the best within emissions standards. I personally like the satisfaction knowing I didn't have to "delete" anything on the bike.

My friend has a 01 F4i with a "GP" style cut away tip thing with no O2 sensor and you can definitely smell the extra unburned gas from the exhaust which leads me to think about the plugs getting fouled up as stated before.

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