Yes I know this is dam near a year old but..... I had the same thing in mine, I got it mapped, went ok, but still a bit slow on initial pick up....put a new maf on, back to normal, probably if I'd put one on first, I might not have bothered getting the map, but what the hell, I've now got 145ish hp from 110...and my god you know it....and even in that size. Yes I know also that that's the basic amout most diesels get now and alot more, but for a 10yr old C5 hdi, it's transformed it. Just the boat like handling to sort out.....well try more to the point