Where is the sensor Port located

I never heard of a "sensor Port". If you meant to say ODBII port, then it is required to be near the steering column. Generally, under the dash next to the column, but within a foot of it.

@georgehodg51826 there is no 1999 Mazda 3 model. The Mazda 3 was not introduced until 2003 for the 2004 model year. Maybe you are thinking of a 323 or a Protege. For the 323 of that year, the OBD socket is above the footrest

For the Protege of the same year, the OBD port is next to the steering column

Now, if your vehicle is a Mazda 3 we'll need to know what exact year it is.