I've had my 2001 S-turbo for about 5 months now and nearly the entire time I have owned it it has had this surging issue under acceleration. I have done a fair bit of internet searching and replaced; the o2 sensor on the exhaust behind offside front wheel (UK car), the MAF metre, Fuel filter, Spark plugs (platinum), Air filter, and had it serviced. None of the above have mad any difference. Had diagnostics on the car at idle and while ran down the road while the problem occurs and no faults are coming up. There's also no signs of any boost leaks. Any information is very gratefully received as I'm out of ideas. Cheers, Will.