the magnuson moss warranty act says no ... they would need to prove the changes caused damage.

but real world experience says otherwise ... it differs from dealer to dealer ... some are super friendly to modified cars while others claim to "blacklist" you for mods so you can't get it repaired anywhere (which is not legal ... they do not have the right to revoke your warranty).

if you run into problems with a dealer it may take money spent on lawyers to resolve proper ... its good to find a dealer that is friendly to your hobby first ahead of time.