Posted this on LPGforum, copied and pasted here.

Just had a phone call from someone at DVSA (took his name but won't mention it here)...

He asked my advice because many owners of LPG converted vehicles have contested MOT failure (due to MIL light being on and since the stricter MOT rules were introduced) because they believe it is normal for LPG converted vehicles for the MIL light to be on. He said he/DVSA had been searching the internet for info on whether this was correct but couldn't find much info, then found my website and it seemed I would be able to answer his question(s).

I told him that the MIL light should not be on on an LPG converted vehicle.
I also told him I was probably shooting myself in the foot telling him the truth, because if DVSA believed it was normal for the MIL to be on it could be a further advantage for owners of LPG converted vehicles at MOT time!

Simon

Not really an issue for us P38 folks since it doesn't have one... :-)

mine is on!
But Simon has diagnosed it so as soon as I can get the sodding lambda sensor off the down pipe I'll be sorted :)
yes, this isn't the P38...

Seems wrong to be linking to an external forum again considering I've done it a few times recently but there's been a few replies on LPGforum including from Gilbert. To avoid copying and pasting more posts, here's the link.. http://www.lpgforum.co.uk/viewtopic.php?f=33&t=14362&p=111885#p111885

Morat wrote:

mine is on!
But Simon has diagnosed it so as soon as I can get the sodding lambda sensor off the down pipe I'll be sorted :)
yes, this isn't the P38...

Which is kind of a point for the position that LPG vehicles should fail the MOT if the MIL is on...

Yes I agree 😀

Morat wrote:

mine is on!
But Simon has diagnosed it so as soon as I can get the sodding lambda sensor off the down pipe I'll be sorted :)
yes, this isn't the P38...

I'm guessing it's seized in its hole?

This happened on my girlfriends car and I had no luck whacking the spanner with a hammer because the exhaust moved too much and reduced the force of the blow.

I used a ratchet strap around the exhaust and some other fixed part of the car, pulled it tight to take the movement out of the pipe. This allowed the full force of the hammer blow to go into the spanner/sensor and it came free very easily :)

It came out eventually. Luckily I spotted a set of crowsfoot sockets in the autofactors when I was picking up the lambda so I was able to go Full Retard mode without rounding the thing off :)
Having just moved house I couldn't find my long bar so I had to use a normal ratchet. Until it came time to put the tools away and there it was - of course.

O2 swapped, Petrol injector swapped, light off and starting/running on six and closed loop. Victory!

Last set of crowfoots I bought came with 2 of the same size so I got a set with one size missing. But when I've needed a crowfoot for lambdas in the past I've cut a spanner up and welded an old socket to the ring end. If you know the lambda is duff you could even cut it down and use a socket on it but I went with the ring end of a spanner so I could re-use the tool I'd made on easier to remove lambdas without cutting the lambda down or cutting it's plug off, just cut a slit in the ring end for the wires to slot through. Not something a SnapOn tool snob would probably do, which is one of the reasons I don't buy overly expensive tools that in practice aren't much better than some far cheaper but decent brands. If I lose a tool worth a couple of quid on an inaccessible part of a drip tray where it won't cause any damage if it shifts, fak it, don't want it to be worth my time retrieving it.

So glad i'm not the only one!
Somewhere in merry England, there is a series 3 driving round with a spanner attached to the underside, where it fell and got wedged and my overly large mitts couldn't get to.
As it was a cheapie, didn't mind losing it. The Snap-on's though.....