O2 sensor the best fuel programer?

Hi guys
A local shop is welding and tapping a metal piece in FMF pipes so the stock (non US) O2 sensor can be screwed, a friend has one of these done on his Q4 with an air box mod and the bike runs great

Why isn't this more common? even if you don't have one in your stock pipe O2 sensors are only around $40 Seems a more reliable way to get the right amount of fuel into the bike short of putting the bike on a dyno

What are your thoughts?

My thoughts are I have been thinking that it makes sense as you say. I asked about a dyno tune at my shop but they don't want to mess with a 250 thumper and besides the dyno is $300 and you can buy a wideband AFR for $420 from Dynojet.

I have more in farkles now than the bike I think but if something happens to the bike I can move them.

combo wrote:

Hi guys
A local shop is welding and tapping a metal piece in FMF pipes so the stock (non US) O2 sensor can be screwed, a friend has one of these done on his Q4 with an air box mod and the bike runs great

Why isn't this more common? even if you don't have one in your stock pipe O2 sensors are only around $40 Seems a more reliable way to get the right amount of fuel into the bike short of putting the bike on a dyno

What are your thoughts?

I did the same with my FMF PC4 from the US to get the O2 reinstalled. I noticed a difference in the bikes running from when I first put the pipe on (it had a hesitation spot when you flicked the throttle and on take off) but by the end of the days ride it had adjusted itself so suit the new pipe as the flutter and dead spot had gone. Runs sweet as now!

This is exactly my question!
All pipes in the UK (& probably EU) must have an 'E' stamped on them, showing the pipe conforms to european law. Anyway, when the bike gets tested after 3 years from new, it must pass emissions. As far as I know, this would mean either keeping or reinstalling the O2 ('Lambda') sensor. So, can one use, say, an FMF or Yoshi slip-on silencer (sorry: 'muffler' for our trans-Atlantic cousins!), in conjunction with existing O2 sensor, WITHOUT an FI programmer, with the net result of maybe 10% more power, better throttle response, better torque, but at the same time not running the motor too lean or causing other damage??????
Just trying to save £££££ I don't have, but having fun!!!

mash100 wrote:

This is exactly my question!
All pipes in the UK (& probably EU) must have an 'E' stamped on them, showing the pipe conforms to european law. Anyway, when the bike gets tested after 3 years from new, it must pass emissions. As far as I know, this would mean either keeping or reinstalling the O2 ('Lambda') sensor. So, can one use, say, an FMF or Yoshi slip-on silencer (sorry: 'muffler' for our trans-Atlantic cousins!), in conjunction with existing O2 sensor, WITHOUT an FI programmer, with the net result of maybe 10% more power, better throttle response, better torque, but at the same time not running the motor too lean or causing other damage??????
Just trying to save £££££ I don't have, but having fun!!!

Short answer is yes, the mate who done is a mechanic and explained it to me in detail and his bike proof the 02S works without problems and finally, if the precious metals die out in the 02 sensor the bike will run rich so the bike will never lean out

Another thing I should mention his bike WRR is as efficient as mine, we both get around 170k's before the fuel light comes on mixed riding, mine is a stock 08 and his a 10 with a FMF Q4 w 02S, full airbox mod & exup/ais removed

mash100 wrote:

This is exactly my question!
All pipes in the UK (& probably EU) must have an 'E' stamped on them, showing the pipe conforms to european law. Anyway, when the bike gets tested after 3 years from new, it must pass emissions. As far as I know, this would mean either keeping or reinstalling the O2 ('Lambda') sensor. So, can one use, say, an FMF or Yoshi slip-on silencer (sorry: 'muffler' for our trans-Atlantic cousins!), in conjunction with existing O2 sensor, WITHOUT an FI programmer, with the net result of maybe 10% more power, better throttle response, better torque, but at the same time not running the motor too lean or causing other damage??????
Just trying to save £££££ I don't have, but having fun!!!

Hi Mash100,
Here in the UK there are no emissions tests for the MOT test on bikes, it may well be introduced in 2013 , but the emissions will only be applicable for
new bikes from that date on, so no worries for us there,
I am looking for a used silencer/muffler from one of our UK bikes ,
I want to cut the heavy/hot/resrticted catalyst off, and keep the o2 sensor and EXUP valve and mate it to a free flow silencer and see if the motor feels
ok, i find that our uk bikes with o2 sensors fuel very well, and infact PDQ racing at taplow had a 250r on a DYNO that had a powerbomb and FMF Q4
and the tourqe curve was not as smooth as stock,
sometimes unless you go the full hog , ie exhaust, fi programmer, airbox mods, dump the ais, ect, it can be best to do ALL , or nothing,
its very easy to spoil whats a very smooth and ecomnomical bike,
But that only my opinion

V-tec

Hi guys.
Iv put a two brother amplifier on my toy and I have cut and chopped the old and new pips to re fit the exup and O2 sensor. The bike is a real giggle.I have made my own baffle to make the bike a bit more sociable, you could hear me from 5 miles away, cats, dogs running all over, birds falling from the skies.
Sweet little ride that I don't want to get off of now.