Red`i` and diagnostic cable info please

Hi, two little questions I could do with some help on. I have a 1999 Audi a4 1.9 tdi. AFN engine. The sticker in the boot says 81KW which I think is 110 hp. The tdi badge and engine cover both have the red i on them. I thought that the red i meant it was a 115hp PD engine but this seems not to be the case. What is the difference between the red i badged car and one without the red i? Also I would like to get a diagnostic OBD cable to suit this car. The OBD socket is at the rear ashtray. It has a 16 pin socket with 3 wires going into it. What cable should I buy. What things can you do with this cable. What software do you need and how much would it cost? Any help much appreciated.

can't help with diagnostics/cable etc.
but as regards the red "i",don't expect much interest !!
it's one of those subjects that people continually ask and people get sick of answering.
i hope i'm not being rude by simply suggesting that you use the search facility, you will
find volumes on the subject,
regards,
stewy.