Hey guys my friend is currently modding his 2001 Cavalier and he wanted to install either a new header (pacesetter or obx) or get a new 2.5 exhaust (burnout or rksport). Which would actually yield more horsepower? He's going to purchase both over time, only has enough money for one currently. Anyway thinks for you time, have a great new year!
Its best to get the cat back first, you might run into pressure issues otherwise.
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Why not buy the header and then save up for the catback, and once he had both he can go to an exhaust shop and have the whole exhaust done at once!
if you want a performance gain and want it now get the exhaust. or do what i did. i got a new cat, header, then exhaust. had it installed and welded all at once
Im a Xbox 360 fanboy...and damn proud of it!!
To be honest... you really are better off installing everything all at once... the bolts on the stock exaust don't like to come off.... and you'll only have to be under the car messing with the exaust once and only make one trip the the welding shop. doing it bit by bit sucks
As far as buying the stuff one part at a time... I would buy the header and cat first (eisier to stick on a shelf) and when you get the cat back... throw everything in the trunk and have it installed.