Sounds like it was incorrectly installed. In the UK the main problem was that the government went with LPG conversions as the cleaner greener way forward, then

Sounds like it was incorrectly installed. In the UK the main problem was that the government went with LPG conversions as the cleaner greener way forward, then got a lot of pushback from car manufacturers who wanted to sell more cars. So in the early 2000s, they pushed diesels as cleaner and more efficient and got everyone to scrap their petrol cars and buy diesels. And you know how that worked out. But the long and short of it is, "what happened to them?" comes down to "they didn't sell enough debt to people" is what happened to them.