how much horsepower does a dual outlet flowmaster add to a V6 3.4L

maybe 1 or two. on my 2001 gt i lost alittle low end power but increased in power after 3,000 rpms. unless you do a 2.5 catback then you might see alittle more but not to much. get some headers then you will see an increase

Ten thousand horsepower. Or one horsepower. Something in between. Maybe. Actually, probably zero.

It will sound faster but not much gain in power over stock muffler,