Hey Peeps, Looking for any advice or direction here! Had my 01 S3 Revo'd and annoyingly its been surging since its been done... It'll surge around 3000 - 4000rpm when changing down to accelerate or sometimes just accelerating for about 5 secs and then the boost will kick in again full swing... So it jolts you backwards with boost as expected, cuts out and jolts you forward, then kicks in again and jolts you back! Surely that's not right is it. The turbo dies completely and it struggles to suck air in but it'll come on again full swing after about 5 - 10 secs... Sometimes I have to down change as it struggles to make any progess accelerating! (running standard airbox with green panel filter which I've checked and is fine). It's not always exaclty on the same rev range and will happen mostly in second amnd third gear gear, but roughly around the higher range... New gen Audi MAF and NGK spark plugs were changed before remap, and so far after it I've changed the TIP to a silicone item and n75 valve but its still doing it. Im also running a baileys re-circ valve (which has some slight oil on the left side pipe is this normal?) Lifting off the pedal it's fine no jerks which would suggest the valve is fine? Checked all breather pipes and hoses for splits, and had a mechanic check to. Its going back people who put my map on in a few weeks, could it be the map ifself?? There saying its unlikey and so are Revo, but has anyone had a problem with a map itself not uploading properelly maybe? VAG-COM shows no fault codes which is even more confussing.. I've done some power runs if that helps if anyone would be kind enough to take a look? Please any advice would be usefull as it's doing my head in!!!!!!!!!!!