hi, am uncertain if this may help you but........... may 2005 bought a 1998 1.9 tdi galaxy has run intermittently like a pig on occasions but when its good its etc etc . 3 weeks ago i happened to bump into a mini cab driver and got chatting at the pumps as you do same model year and so on. asked him how many sensors he had replaced etc etc. reply was, you are in a shell garage have you not noticed how much better your gal runs the day after you filled it at a shell station. lots and lots of memory recalls and....... yep for the last three weeks have kept it full of shell diesel and am thinking of phoning the guiness book of records powers up response is up no hesitation until we get down to a quarter tank, fill up and no problem again old minicab drivers god bless {only when not moving} whats to lose?