i was wondering if you had a shop do a custom cat back exhaust how would that effect the performance versus a brand name catback? in my eyes it would be cheaper but ive heard that custom exhaust can sometimes make you lose hp. buddy of mine did a dyno run before he had a custom exhaust made. than did a dyno after the custom exhaust was finished and he lost hp significantly. he jus ended up buyin a brand name cat back. so has anybody found this out to?