[bluebob]

All cluster instruments (prefacelift and facelift) have fuel computer but it is activated or not. However, if you want to activate it you have to re-program it or change hexa bits in line 1F0. Change bit 9 to D and that will activate fuel computer then change bit 8 to C and it will activate instantaneous fuel consumption. If you don't know how to program it find someone with a proper soft containing fuel computer and activate instantaneous fuel consumption in Forscan.
I guess that it is not possible to change hexa codes in Forscan to activate fuel computer but you can always ask a question on Forscan forum.

PS. Instantaneous fuel consumption can only be activated in facelift software version after 24.01.2004.