O2 sensor fitment

[68C]

The standard fitment for the O2 sensor is into a factory fitted threaded insert welded into the LH side of the x-over.

 

It seems the sensor probe protrudes a long way into the exhaust pipe. This must act as a restriction to the gas flow, a restriction that is only present on one side. One would think having different restrictions between the LH and RH exhaust ducts would affect the back pressures and so the fuel required for each cylinder. Does this mean that only the cylinder that has the O2 probe is effectively running closed loop, the other cylinder just being a probably innacurate 'guess'.

 

1. Does this restriction matter?

 

2. Would it be better to arrange for the probe to have only the tip protruding into the gas flow. This would mean using some kind of extension threaded into the standard port.

 

3. Is the factory bung position in the ideal spot?

 

4. If running two probes (for the MyEcu) would it be best to weld the second boss into the RH side similar to the LH side or is there a better position.

 

I should perhaps mention I have the later exhaust system with the front crossover as well as the perhaps more efficient centre x-over (don't know if it has a name - I hear the earlier version is described as the 'colostomy bag').

[Kiwi_Roy]

SInce there is no way to adjust the injector open time from left to right does it matter if it's only on one side?

 

I had mine welded into the crossover under the gearbox smack in the middle tilted towards the rear.

 

I don't think the sensor tip is a significant restriction but you could just add some washers.

 

Each of the header pipes on my bike has a small plug but the sensor has about an 18mm thread.

[gstallons]

The O2 sensor is located where the engineers thought it would be best located. The sensor protudes into the exhaust stream 1. to get a complete sensor flow of ex. gases across the sensor tip. 2. the sensor has to somewhere . 3. You could weld a bung opposite from the other sensor and install an O2 sensor on that side and leave the wiring disconnected.

The best set-up would be an O2 sensor in each ex. pipe dedicated to each cylinder for sampling that cylinder thus causing the need for individual triggered and pulse-width injectors.

 

[68C]

Your faith in engineers is commendable.

 

I have the MyEcu fitted which can accept two O2 inputs, I am using the standard narrow band Guzzi O2 sensor at the moment fitted into the factory port on the x-over.

 

Of course the MyEcu map needs to be set up for each bike and this is where my worries about the difference in the available pipe cross section between the LH and RH side arose. The problem - if it is a problem - was posted by someone else on the MyEcu forum and as with all doubts has started to worm into my mind.

 

I think I will get two extended bosses and weld them on and blank the original port. I hope to be able to fit them to the input pipes of the x-over under the gearbox. I did see the two ports on the downtubes and wondered about using them with smaller O2 sensors but am mindful of a comment by Luhbo that the bike may start to look a little 'experimental'.

 

So, has anyone practically addressed this matter?

[Chuck]

So, has anyone practically addressed this matter?

 

I personally think this falls into the picking the fly sh*t out of the pepper area.. I doubt that these ditch pumps notice a miniscule difference in back pressure from one cylinder to the other. Of course, YMMV, and I've been wrong before.

[68C]

So, has anyone practically addressed this matter?

 

I personally think this falls into the picking the fly sh*t out of the pepper area.. I doubt that these ditch pumps notice a miniscule difference in back pressure from one cylinder to the other. Of course, YMMV, and I've been wrong before.

[68C]

I was beginning to think the same myself, a 100bhp/litre engine it ain't.

 

Thanks all.

[Yeahoo Whoyah]

My 2004 Cafe Sport USA model is not equipped with an 02 sensor like the Euro spec bikes. It runs great, no flat spots and no poping on deceleration. I suppose I should be thankful for that, right?

[v11cafe]

Right!!!!

[Skeeve]

So, has anyone practically addressed this matter?

 

I personally think this falls into the picking the fly sh*t out of the pepper area.. I doubt that these ditch pumps notice a miniscule difference in back pressure from one cylinder to the other. Of course, YMMV, and I've been wrong before.

 

Esp. as the stock crossover is really a pre-muffler, and the "flow restriction" is probably not even measurable. This might be of concern in a real xover like the Stucchi, but the stock box has so much volume that the flow is likely not affected in the least. JMNSHO