i currently got my car a diagnostic test and it said i have a huge vacum leak on 1998 Volvo V70

and speed sensor causing the speedometer to not work.and a huge vacum leak.

Asked by for the 1998 Volvo V70
It's common for the intake manifold to leak, but it's also possible the MAF sensor is bad and the computer assumes a very lean running condition. There's not enough info to go on to know for sure. I suggest you take it to a Volvo tech, they will be quite familiar with the issues you are experiencing.
Also, the speedometer issue may be a bad ignition switch or ABS computer, again, have a shop look at this.
Thank you very very much Bret, i appreciate your responce. I wish you and your family a very happy and Merry Merry Christmas and a prosperous New Year!!!!