How much does it cost for a muffler and resonator delete?
Price to Delete
Because both the muffler and resonator require a similar amount of labor and a replacement pipe of roughly the same length, both will cost nearly the same to delete. You should expect the cost to be anywhere between $50 to $300, with most shops charging around $100. via
Does a muffler delete affect power?
So for most cars, the muffler delete will not add any power. Some cars will gain some power, but generally it's not much, usually under 5 horsepower. However, if you have a car modified for more power, and still has the stock mufflers, then you'll have more gain. via