Lamda Probe

Help! - Has anyone had to replace a lamda probe? My one has disintigrated this evening and will need to be replaced. How much are they, where is the best place to get one?. There were previous threads suggesting that the bike could run fine without it , is this the case?

RB

Hey Roy,The bike should run without the sensor-but only just.Best bet is to order one from motorworks or something or mabye ask clarks or calterdon parts dept on the offchance there cheaper.As long as you can take the tank off to disconnect the sensor and take the cat or y piece off its not hard.By the way the sensors are usually bloody tight so use the correct size of spanner and watch yer knuckles.

I replaced mine - they cost about £80 new but I bought a second hand one from www.motorworks.co.uk for £30. It didn't work properly and had it replaced without question.

Keep a lambda probe on the circuit. If you run without it you will damage the cat. Except in the following cases...

If you removed the cat you could replace it with the CO potentiometer from the earler GSs but running it without either richens the mixture excessively and kills what little economy the beast has.

Assuming that you already removed the cat, if you use the BBPower chip contact the manufacturer to confirm whether the probe should be disconnected for your version of chip. If you use the Techlusion FI box you do not use the lambda probe.

yo city

I'm a bit confused about all this.


I know we have exchanged on this subject before.

Can you clraify exactly what the lambda probe (o2 sensor ? ) does ? and why you don't need one with the techluision. and whats closed loop ?

dave

The lambda probe measures the temperature of the burnt gases and from this can determine the efficiency of the engine and therefore how much fuel it needs.

Closed loop is where the fuel injection system is managed by the lambda sensor. Fuel input is determined by the probe. This is at tickover or very low throttle openings when cruising.

Open loop is when the actual map on the chip comes into play. This occurs at rpm greater than about 1500, or, when you whack the throttle open. The lambda sensor is ignored and the motronic uses the pre-determined fuel inputs from the map in the chip.

Some people feel that the motronic has a problem in determining whether the bike is at tickover (closed loop) or cruising at light throttle and I think this is where surging occurs for some but not all. If you have an agressive riding style and tend to swing on the throttle, the closed loop rarely comes into play.

One point which I cant get to the bottom of is, some people think that if the lambda probe is disconnected (when the bike is in standard trim and has not had another chip fitted) the motronic defaults to base mapping. Which may be the "get you home" loop. If you have an aftermarket chip in, then disconnecting the lambda may be OK. Expecially if the manufacturers recommend this. One must assume that they have taken any "base - get you home" mapping out.

Disclaimer:
Please feel free to ignore this information as usually I dont know what the f***k I am talking about.

Thanks chaps,
Motorworks have come up trumps and I am expecting the probe tomorrow.
RB