Fiesta ST Downpipe Thread

[iso100]

Hah. I was referring to the God of Boost that watches over all things forced induction. His love does not discriminate based on impeller size. He does, however, have a special hate for crush-bent "custom" exhaust systems.

 

[Sekred]

I was talking about the elbow size, nothing about upgrading the exhaust or not. Next time you see Jay, tell him I said hi.

Thanks for the copy paste of a post that has been all over the internet for at least five years though.

Jay Leno?, sure I saw him down Walmarts last week.

 

[razorlab]

Jay Leno?, sure I saw him down Walmarts last week.

No, the guy you quoted.

 

[Sekred]

No, the guy you quoted.

I got it buddy

 

[rastok]

whats the cel your getting after changing the stock dp.. and could it be possible to relocate the o2 sensor further down on the line to avoid getting any cel..

i had 2 cat on my truck, i gutted the one on on the manifold and then relocated that o2 sensor after the second cat and bingo no cel..
could this work??

 

[Kip2MyLou]

I Probably don't change my exhaust if a buy a downpipe because I like the sound of the OEM exhaust and for the moment I don't need more sound!

Is it a good buy (Downpipe) if I keep the stock exhaust?

Thanks.

I was curious about this too. I'm about to purchase a downpipe and was wondering if it's worth it if I'm going to maybe keep the stock exhaust?

Another quick question, I just moved to Maryland where do emissions and was wondering if that will affect my choice between catted or catless? Thanks for info!


And another question, kinda new at this again, what's the pros and cons against catted and catless?

 

[iso100]

Another quick question, I just moved to Maryland where do emissions and was wondering if that will affect my choice between catted or catless? Thanks for info!

Where are you in MD? I'm directly in the center of Baltimore, DC and Annapolis.

In MD they just scan obd codes. I think you'll be fine as long as you have a tune that disables the CEL.

 

[Kip2MyLou]

In Gaithersburg. And okay. Thanks.

I had an downpipe on my Veloster and I never got the CEL light because my mechanic switched over the O2 sensors from the stock set up. Can the same be done with the Fiesta?

 

[iso100]

They are supposed to be moved but still throw the CEL. The computer is just really picky.

 

[Kip2MyLou]

Damn that sucks. I didn't have that problem with my veloster.

And I don't know if anybody saw my last post but what are cons and pros of catted vs catless?

 

[Kip2MyLou]

Before I purchase these cobb downpipe are any other people having problems with removing the stock one and replacing it with an after market one?

 

[aballphoto]

Ok, stupid question but I'm confused. I've read that for downpipes you need a tune, but in my experience with other cars this is not true. Sure you wont see full potential, but not a requirement. Are these cars different for some reason I am not familiar with?

I work for a company that builds Audi and Porsche Exhausts, so we have 200 Cell HJS Catalyst sections laying around, I'm thinking of getting our prototype guy to build me a downpipe one weekend but, I wont bother if I need a tuner first. The reason I even thought about going out of order is because we just happened to have some cat sections that are the right size.

thanks in advance.

 

[JPGC]

Ok, stupid question but I'm confused. I've read that for downpipes you need a tune, but in my experience with other cars this is not true. Sure you wont see full potential, but not a requirement. Are these cars different for some reason I am not familiar with?

I work for a company that builds Audi and Porsche Exhausts, so we have 200 Cell HJS Catalyst sections laying around, I'm thinking of getting our prototype guy to build me a downpipe one weekend but, I wont bother if I need a tuner first. The reason I even thought about going out of order is because we just happened to have some cat sections that are the right size.

thanks in advance.

You could drive the car without a tune. It won't be optimized and you may get a check engine light depending on the replacement downpipe. Other than that, I don't see it causing any damage or other issues.

 

[aballphoto]

You could drive the car without a tune. It won't be optimized and you may get a check engine light depending on the replacement downpipe. Other than that, I don't see it causing any damage or other issues.

Ok, thats exactly what I thought. Thanks for the help!

 

[TurboRon]

I was curious about this too. I'm about to purchase a downpipe and was wondering if it's worth it if I'm going to maybe keep the stock exhaust?

Another quick question, I just moved to Maryland where do emissions and was wondering if that will affect my choice between catted or catless? Thanks for info!


And another question, kinda new at this again, what's the pros and cons against catted and catless?

I am in the same boat. I do not want to get much louder than the stock exhaust note, but would love to free up the Fist exhaust as much as possible. I'm hoping a DP with stock exhaust will help. Someone please post findings?!?!?
Injen Technology came to the rescue with their SES exhaust yielding big power gains and minimal increase in noise on my Evo 9. by contrast initial sound clips are very loud for their FiST exhaust.
So far Cobra sport seems the least intrusive of the sound clips I've heard for a cat back IMHO. Maybe doable.
But I would give my left nut to see some dyno data on catless DP with stock exhaust vs DP with 3" catback

As far as cat vs non cat:

Non cat / catless - Pro's: less restriction = more power.
Conz - not approved for street use, causes emissions issues in testing states may not pass, more smoke and unpleasant smell and greenhouse gasses, can cause CEL / check engine light without a tune. Solutions: (a defowler bung or relocating the o2 sensor can also fool the computer and prevent light) I had an electronic unit in the Evo that fed a "happy" signal to the ECU. Might not be long before an enterprising individual figures an electronic one for the FiST.

 

[Kip2MyLou]

I'll be going exhaust and intake before downpipe and intercooler. Then I'll see how I feel about the power and go from there. But the cobb exhaust seems to be the best audible sound, at least in my eyes. Just need to save up some more cash.

 

[TurboRon]

LOL ! I will likely do just opposite! ... 1st - DP with stock exhaust, and a drop in filter with stage 1 AP tune.
Then if I'm still restless, ... stage 2, FMIC & piping for just a nice extra kick but keeping it on the quiet side for daily driving.

 

[masonsturbos]

How do you get around inspection and emissions with a catless dp?

 

[Siestarider]

I have some logs posted under self tuning section, short version is my trial and errors data say get a good IC first if you are in a hot humid climate. Then downpipe. I currently run Cobb IC, 2J DP, Mountune Intake and Cobb S3 tune 93 gas with OEM exhaust. Plenty of juice for right now. My data show this setup does not benefit at all from the 3" cat back I had on, so I removed it, much stealthier now.

Doing your own DP install is difficult even with all the good guide info on this forum, but once you do it, future work is a lot easier, lots of little tricks learned by doing it help. Being rid of OEM cat heat shield helps too. Be sure to keep OEM exhaust manifold heat shield, I tried leaving it off and heat hurt performance, so back on it went.

Each state has its own rules on inspections, but my understanding is a catless DP is illegal on street regardless of state.

 

[masonsturbos]

How do people get away with it then?