Rep Power: 369

well I finally fixed my header problem... got a temporary replacement bolt to hold the upper section of the header to the downpipe...

now it runs just like stock. dont hear anything different or feel any difference in performances. in fact I didn't feel any low end gone... well, I'll drive it some more to see if there's any difference I can detect.. (obviously my butt dyno doesn't tell squat, but I've drive the car for quite awhile now, so I know what rpm goes with what speed.. and how the car behaves...)

when the header was leaking, I felt a performance increase though. that was fun. heh. the car sounded horrible too... it had that deep exhaust tone.. and also a rattling hissing noise to go along with it... but I was pretty close to running open header, and the car sure felt faster.

I can imagaine swapping out the stock upper section header, and the downpipe (a pipe) thats welded to the cat convertor with the HP 4-1 header with "high flow" cat will yield some significant results... course the high flow cat isn't a high flow cat at all, just a straight pipe.

if you dont want to go with the hard route of getting those back ordered HP header and trying to get it to fit...

u can just opt for a aftermarket upper section header... and get a downpipe thats been sold on ebay... with an o2 simulator... should give you decent gains too... (probably not as much as the 1 piece hp 4-1 race header, but should be the same as their redesign 2 piece...)

and probably get a wee bit more out of the system if you opt for an aftermarket cat back too...

but all in all, the stock exhaust system isn't so bad. if you look at it, everything is pretty darn straight.. and in a sense we have a stock 4-1 header setup... (well for the ex anyway) and if you compare the stock oem 4-1 header to previous gen headers.. you can tell they put a bit more work to it... (ie: actually seperating each pipping..)

when you swap out a cat convertor in any car, and go with an almost straight pipe setup, you will of course yield decent gains in performance... but you'll also be pumping out some smelly o2 fumes... and ruining the enviornment and what not.