I purchased a 2008 van five weeks ago from a private seller. I checked the MoT history online before buying and it had an immaculate record, without any problems. Three days after buying it, the engine light came on, and I've now discovered from two mechanics that the catalytic convertor and majority of the exhaust are missing. A previous owner converted the van to an LPG fuel tank and then back again to petrol but did not put back the catalyst and exhaust when converting back to the petrol tank. I believe that the lady I bought the van from knew that this was the case, but did not inform me. My mechanic tells me that in it's current condition, it will not pass its upcoming MOT, so I believe that the seller's mechanic was passing the MoT's illegitimately. I now need to spend around £2000 putting the van right to pass the MOT. Where do I stand?