Which diagnostic tool should I consider for my car? Good value for money would play a big role.

 

what do you want to diagnose? If all you need to do is read P codes, a $29 unit works fine. If you want to read ABS / chassis codes add another 50-75. If you want to read even more diagnostics like SRS codes add another 50. If you want to run full Volvo proprietary diagnostics etc, you can pick up a VIDA DICE clone with theftware software via EBay (only works on pre 2015 volvos) I think Foxwell, Autel and iCarSoft all offer a Volvo proprietary model in the $200 range.

 

I would want to do EGR, DPF and CAT delete (but it seems this is not a matter of "click here and there"), read DTCs, recalibrate fuel consumption report on the dash to be more accurate, clear "service required" message.

I'm not a commercial workshop, this is for my own car, work being done by myself.

 

you are talking about changing the ECU program itself, which is more what tuner software does than an OBD2 code reader. VIDA DICE is what the dealers use for updating software etc but afaik they don't use it to change fuel maps. To do that kind of stuff, you would probably need to research ECU tuning programs. Not sure if there is such a thing for a D5 since there's not a big market for that - but you can google around for Volvo ECU tuners to see who if any have something for your engine/year. Otherwise, check out VIDA