I have a Citroen Xsarra Picasso 1.6 HDI (56 model). About 5 weeks ago, my car just stopped on me when driving and the low oil pressure message and engine light came on. After a couple of minutes, the car started up again. Two weeks later it happened again, and I took it to my garage - the mechanic there was unable to read up what the code meant, so he cleared it and the car was ok again. Last Thursday, on doing a 42-mile drive, after 10 miles, the car started spluttering and jerking and sounded really loud. It kept this up for the rest of the journey (happened about every 2 miles or so). I parked up the car for two hours and then had to drive back home. The car was ok for 10 minutes then started up the spluttering, jerking, etc every couple of miles for the rest of the drive home. I drove it to my garage the next morning and a mechanic drove it around the block and came back and said that it was driving fine! They told me to drop it off this Thursday as they need more time to look at it, however, they did say that they thought it could be a turbo problem (a friend suggested a possible sensor problem). I drove the car home (about a 10-minute drive and had no problems). I drove it to work yesterday, it was fine, driving home it cut out on me going around a corner and all of the lights came on. I started up the engine and it started straight away, however, driving home for the rest of the journey, the car was spluttering, jerking and sounding loud like it did before - only just managed to get it back to my house. I haven't driven the car today, but will try to drop it off to my garage tomorrow night when the roads are quieter, so that that they can look at it on Thursday morning. Any ideas about this, please? Thank you.