Does it effect your performance if you run a header with a stock cat convertor??
yes it does it restricts the flow because it has to take the exhaust down to the stock piping size
So since i have 2 1/2 cat back exhaust, once i my dc sports header what size high flow cat will i need?
get the 2.5 to go with the catback
alright thanks alot i appreciate it
how much gain would you expect from an aftermarket CAT over stock one?
Im no expert, but i'd say between 3-8hp...maybe more, maybe less. Its different on every car....the dyno is your friend
i have heard putting a high flow cat on messes with the backpressure and not in a good way meaning a loss in power, any one ever hear of this issue? by the way 2.2 ecotec is what i got,