I've been doing some t'internet research but can't find the answer to this one .. probably using the wrong words in google ..

LPG (UK) is a mixture of propane and butane
GPL (France) is also a mixture of propane and butane ..
The question is .. are the mixture ratios different to any major degree

The reason for the question is relatively simple ... running a 3.2 it is said that it is not a matter of "if" a fault code 0420 or 0430 occurs but "when" ... however since the LPG conversion I have only had this error twice in 18 months, and each time it has occured one week into our French holiday.
Easily corrected using the resetter, but I find it a tad too coincidental that just a few days after refuelling in France I get the error again.
It can't be French petrol as we didn't use any, we have towed similar distances, and more, without the problem in the UK, so I'm just wondering if a difference in the "mix" could upset the calibration of the lamda's ??
If it does then this might give a clue as to why some 3.2's get the problem on petrol and others don't ... comes down to fuel quality ??
Any knowledgeable folks care to add their thoughts

