Its an OB1 and word for word the printout on my sales document said "checked for stalling, checked all connection to sensors and checked engine electrics with 5051, reset all fault codes (5 in total) rosd tested, only one fault still in the memory (o2 sensoe exceeding limit)" I'm glad to see you got yours sorted Ben, I wish mine had been cured so simply !!!! I forgot to clean that little box, I think its the silencer, was it easy to do ? Standard air box is going in next week anyway so I'll take it from there I suppose once its been on VAG-COM again. jules