Downpipes on stock exhaust system

[yowen]

Hey guys, I used to be on the ecoboost owners forum and discovered it's pretty dead these days, so here I am! All I've done with my car so far is put an Airaid CAI on. But I am planning on more mods. I definitely want to get a tune, but currently I am hung up on what to do as far as downpipes go...

I find myself wondering what it would be like to have downpipes on the stock exhaust system. I was considering going catless, until I read on here that it can produce a rather nasty smell... Would that also be true with the 3rd cat still in place? How would that affect noise levels? As I also read on here that catless downpipes can produce quite a bit of noise.

What do you guys think? Not a good idea to go catless? Would my 3rd cat alone be enough to mitigate the smell factor. How noisy would it get? I'd like a little more than stock, but I'd like it to stay civilized on the highway. Thanks for your help!

 

[4DRHTRD]

I used catted pipes so I could guarantee the passing of emissions, I have ZERO smell with these downpipes unfortunately they're the most expensive ones but they're awesome and the cats are only worth about 3HP worth of loss.

 

[yowen]

I used catted pipes so I could guarantee the passing of emissions, I have ZERO smell with these downpipes unfortunately they're the most expensive ones but they're awesome and the cats are only worth about 3HP worth of loss.

I am in Michigan, so i have no concern with passing emissions testing. Just wondering if the smell/noise are going to be as noticeable as some other people were commenting. I would love to save some money toward other upgrades by going cat-less, haha. But I'll spend the money if I have to, haha.

 

[4DRHTRD]

I can't comment on them, I just know mine don't make any smells even at 600HP on E85.

 

[SHODYOU]

I have no cats and mine doesn't smell... even sitting in traffic dead stopped for a while with windows down youd never notice it.

And its still quiet as well... louder than stock but still not loud.
I have o/r dp's, 3rd cat/resonator delete but I replaced it with a magnaflow x miffler, and dynomax axleback.

 

[yowen]

I have no cats and mine doesn't smell... even sitting in traffic dead stopped for a while with windows down youd never notice it.

And its still quiet as well... louder than stock but still not loud.
I have o/r dp's, 3rd cat/resonator delete but I replaced it with a magnaflow x miffler, and dynomax axleback.

Interesting, I wonder what's causing the difference between you and some people that have commented on the smell of running catless...

PopolZ: totally catless here! the noise and smell can be annoying at times.
darreli: Noise..yes...inside the cabin. Smell..yes..on the outside, however, sometimes you can smell it on the inside. Neither of which i am fond of

these are from this topic: http://www.ecoboostperformanceforum.com/index.php?topic=828.0

 

[SHODYOU]

No idea... only resonance I get is right when I crank it in the a m when car is dead cold and car idles a little high, 1k-1200 rpm but once it settles it goes away and never happens when I'm driving.

As far as smell, I'm sure if I stood behind car for a bit I'd notice but while driving it has yet too. I've been sitting in ridiculous traffic all week as I came down to Cruisin The Coast... not once have I been self aware of my exhaust.

I do come from a Mustang back ground tho and I haven't ran cats in years... so maybe my nose isn't as sensitive to it as others.
That said, gf and mom have both ridden,  gf a lot... neither has commented/asked about noise or smell.