Let's talk downpipes

[Misordia]

So I'm looking into replacing my stock DP with something else. Question being, with different vendors selling DP's and pricing being +/- $50, is there much of a difference with these DP's other then some being catted and some not? I was looking at the ATP cat less for $250 and was wondering the performance difference between that and something like the $300 Madness DP. Also is anyone running NorcalSS modded DP? If so, how much louder is it and is power noticebly different? Sorry for the noob questions and thanks for the feedback!

What im looking into getting.

http://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=ATP-FIAT-001&Category_Code=FIAT

[gundam2000]

I plan on taking my factory down pipe to a shop and having the outlet made bigger. maybe 2 inch.
You keep the stock cat so no codes and get 75% the gains of going to an aftermarket downpipe.

as for what is available I believe all of them have a chance of throwing codes, catted or not.

[Misordia]

I'm actually considering doing NorcalSS DP mod. He can bore em out to 2.25 or 2.5 but my question is if I can run with stock exhaust/midpipe.

[gfurneri]

In most cases your going to through a code/ check engine light if you go cat less. A lot of people like the rrm catted dp, because in most cases you won't through a code. The Vendor NGEN has a great way around the code by using a big daddy mini cat and a o2 sensor spacer if you go cat less. ATP makes a great dp and so does rrm. NorCal Ss mod is legit and is worth consideration.

[Purgatory]

I will testify to that. Been using the RRM Catted DP for a full year now (along with a lot of other engine mods), still have never thrown a code, ever.

[doni_m]

I have the 500 madness catless downpipe. Its a great piece and sure does make nice noises. It gets raspy at higher rpms but that's cause the rest of the exhaust is stock. I had their o2 spacer but broke off as I was tightening it down so I still have the code. Overall pretty satisfied.