Lambda sensor - in or out?

[adamski49]

Pro Boxer - you may be able to answer this one.

Apologies GS people but this question concerns my S (although it's probably applicable to the GS as well) and I can't seem to get a definitive answer elsewhere.

When removing the cat is it ok to leave the lambda sensor disconnected? Numerous S owners report better performance and no backfires with it removed.

Mods I have made are:
Laser Y piece (standard end cans retained)
BB Power chip (set to stage 2)
K&N air filter (awaiting delivery from Motorworks)

The sensor is currently disconnected and the bike runs ok - a quick 5 mile test ride up to 90 mph show the motor spinning up quicker, no backfires and a happy tickover.

Slightly less bottom end, though this may have something to do with no snorkel or side panels attached effectively leaving the air filter open to the fresh air.

Two dealers I have spoken to advise that the sensor should be connected for better fuelling and as the laser does have provision for it's installation this makes sense. If it only affects the closed loop (tick over / low speed cruise) range I can't see it being a problem... it'd be nice to have an answer before I put it all back together though.

Cheers

Adam

P.S. I've already searched through earlier threads but no definite answer as to which way to go and Pro Boxer appears to be an extremely knowledgeable chap regarding these matters.

 

[Phil Reynolds]

When I put a Y piece on my GS, I left the probe off. Result? better eveything, and no noticable difference in fuel consumption.

Conclusion? dump the Lamda.


Hope this helps

 

[Sergeant Pluck]

i reconnected mine when i swapped over because i'd heard that without it the engine can run very lean and cause all manner of heat/valve related problems. which i find particularly worrysome! having said that, my sources could be wrong - it would be lovely to get a definitive answer....

pr0ne

 

[Deleted account 210609001]

1150GS Y-Piece

I've just ordered a Remus Y-piece. I intend to keep the standard silencer (for the time being, at least). Thise nice people at Motorworks advised that the lambda sensor is simply removed at the connecter further up the line and the sensor itself left in the original collector/cat.

Anyon ehave any defintiive views on this, or any other advice in fitting the Y-piece to replace the collector box?

Does the injection need anythign doing to it? I have read that it doesn't, but some independent reassurance would go down well! How does the injection know there is no cat fitted, or doesn't it need to know????

Finally, will it make that much difference to performance?

Thanks

Robin.

 

[kamae]

lam sensor

hi ive got the remus y piece,road can and bb power chip.before i got the chip fitted i was told by remus that you leave the sensor in,but when you fit the bbchip you disconnect the sensor.i ran with it connected for 2yrs then got the chip fitted.cheers paul.

 

[slimbo]

ok you lot pin back yer lugoles,
the lambda sensor is vital for the efficient running of the bike as without it the ecu cannot adjust the mixture whilst running and will only run on a base setting.....
the lambda sensor sniffs the exhaust gasses for oxygen (hence its other name the oxygen sensor), if it is high in oxy then it is too weak so it increases the duration the injectors are open thus more fuel. if its low oxy in the gasses then it will do the reverse and weaken the mixture so as to keep the balance of optimum fuel air ratio!! see its simple... this adjusting is happenning all the time the bike is running , you could say that its tuning itself on the move.....
so junking the cat is good junking the sensor is not good..
we all of us know what a cat does (no mike o it does not meow!)
and it is a restriction in the exhaust system so by removing it gasses flow more readily and this tends to weaken a fixed mixture.
but with the use of the oxy/lambda sensor then all will be good in the world......



right time to lay down
as my head hurts....
:goof

 

[bandit]

And another thing !

There doesnt appear to be any hard facts on the Lamda sensor.

BBpower recommend disconnecting the sensor.

With the sensor connected the bike obviously runs rich on the overrun, hence the propensity to back fire when the cat is removed. (or is it the sensor is too slow to react to the fact that you have shut off the throttle !)


I would strongly recommend that if you do make changes such as cat removal, race pipe, K&N, BBpower, Techlusion, lamda removal then get it dynoed. The mixture will be checked on the dyno to ensure that it doesn't run lean.


I have all of the above on my bike. The dyno was free when I bought the techlusion.

So what are the simple facts ?

The lamda sensor is testing for how efficiently o2 is being burnt. Too much o2 means it should tell the eprom to add more fuel. The lamda is constantly cycling, hence surging on some bikes.

The teclusion adds more fuel on top of the eprom, hence making the Lamda redundant.

Well that my 3 euro's worth anyway.

Dave

 

[adamski49]

Still confused / not entirely convinced

Pro Boxer - you seem to have disappeared.

Any thoughts on the above?

Thanks

Adam

 

[adamski49]

Let's add some confusion!

Just spoken to TTS about getting a Techlusion fitted and asked about the Lambda sensor - not important apparently, only affects the tickover and low rev range.

They advised me to go for the cheaper Techlusion unit (the FI 1030 over the R259) as I could then forget about the sensor.

More interestingly they said to remove the BB Power chip and revert to the stock chip as this would give equally impressive results and they would have a better idea of the base setting to start from.

I think my brain's just gone into a flat spin

Adam