If I only change 4 spark plugs out of 6 spark plugs on v6 will it effect the ca? on 1995 Toyota Avalon

None of the spark plugs went bad or anything like that. I am doing a whole tune up and wanted to know if changing 4 plugs instead of all 6, will doing that have any negative effect on the car? The other 2 plugs that didn't get changed are still OK and have had no problems. Just would like to know asap so I can know if I can start it up when tune up is all complete.

Asked by for the 1995 Toyota Avalon
2 answers
Wont hurt anything. But sooner or later those other 2 will have to be changed as well.
why would you do that?