Pipes-A-La-Piggie: DIYer at Luch
 

I just thought i would do a post and add a few comments on this common mod.

1st- These tools should be added to the list of tools needed. BFH and thick bar , also step downs.
<img src="http://pictureposter.audiworld.com/99442/104_2250.jpg">
2nd- Instead of using a huge drill, use a step down for the hole when relocating the O2 bung.
<img src="http://pictureposter.audiworld.com/99442/104_2248.jpg">
3rd- BFH and bar are used to push out cat-cell out the back side where the cut was made. You can see the removed cells here, I drilled few a holes just to release some pressure. For the most part they came out whole. I took the time to clean up the insides as well.

<img src="http://pictureposter.audiworld.com/99442/104_2247.jpg">

Other than that, the write up was helpfull, it's pretty self explanitory anyways.

Finished pipes going in tonight or tomorrow.
<img src="http://pictureposter.audiworld.com/99442/104_2249.jpg">

Nice work, all on your lunch hour! Impressive. Now put those bitches on!

Nice, how did you get them precat materials to come out in such nice big chunks?

I am still waiting for someone to do that to some of the RS4 DPs that were imported to the US
 

I still got one set left ;-)

just get the non foulers to keep things easy (no splicing extra wire in) and clean-ER ;)

i can do it .

I had read somewhere about problems, this was that complicated anyway.

Read again, I hammered them out when I had the pipes open.

oops wasn't

;)

Piggies require new gaskets when installing? Get them at dealer?

what's the size difference between the two?

not really needed ..

not unless you deystroy the original gasket do you need to replace it

STFA! just kidding. Here's the DP FAQ that I did a while back
 

1. Inner Diameter
2. Removal of Pre-Cats?
3. O2 sensor location fore and after cat? (if cats are doing their job, you won't get a CEL. Some tuners also will reprogram the chip to ignore this code too - ie test-pipe option-chips)
4. Test-Pipe Option?
5. Flex Joints?
6. Cat Type
7. Cost?

So now how does each option (that I'm aware of) stack up?

<b>Stock System</b>
Diameter = &lt;2.25" (I believe)
Pre-Cats = YES
O2 Sensor location fore and aft of cats = YES
Test Pipes = NO
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = Pre = Metal, Main = Ceramic 400cel
Cost = Nothing, you already have them.

&lt;b&gt; Piggie Pipes - OEM with gutted precats&lt;/b&gt;
&lt;a href="http://www.s4biturbo.com/art-piggiepipes.shtml"&gt;Piggie Pipes&lt;/a&gt;
Diameter = &lt;2.25" (I believe)
Pre-Cats = Not anymore
O2 Sensor location fore and aft of cats = YES, often relocated 2nd O2 sensor to behind main cat
Test Pipes = NO
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = Main = Ceramic 400cel
Cost = stockers plus labor.


&lt;b&gt;APR&lt;/b&gt;
Diameter = 3.0"
Pre-Cats = NO
O2 Sensor location fore and aft of cats = YES
Test Pipes = YES
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = ?
Cost = $1499
<img src="http://ctny.audiworld.com/mark/s4/downpipes/DSC04667.JPG">

<b>AWE</b>
Diameter = taper from 3" to 2.5"
Pre-Cats = NO
02 Sensor location fore and aft of cats = YES
Test Pipes = YES
Flex Joints = YES (ball/socket joint)
Cat Type = 400 cell per inch Ceramic Matrix
Cost = $1595
<img src="http://www.awe-tuning.com/media/products/awe/awe_s4dp_sm.jpg">

<b>JP Engineering</b>
Diameter = taper from 3" to 2.5"
Pre-Cats = NO
O2 Sensor location fore and aft of cats = YES
Test Pipes = NO
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = Carsound (400cpi Ceramic)
Cost = $1350
<b>ANYONE HAVE A PIC?</b>


<b>Milltek</b>
Diameter = 2.3" (60mm)
Pre-Cats = NO
O2 Sensor Location fore and aft of cats = YES
Test Pipes = NO
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = continuous stainless steel cores 200cel
Cost = $1865
<img src="http://www.stratmosphere.com/milltek_s4_dpandcats_fullset_320.jpg">

<b>MTM</b>
Diameter = ?
Pre-Cats = NO
O2 Sensor location fore and aft of cats = YES
Test Pipes = ?
Flex Joints = YES (not sure what type)
Cat Type = ?
Cost = $6900 (part of there Stage 3 package)
<img src="http://www.avalonmotorsports.com/store/uploads/dpipes_s4_mtm.jpg">

<b>RS4</b>
Diameter = 2.3inch inner diameter
Pre-Cats = YES
O2 Sensor location fore and aft of cats = YES
Test Pipes = NO
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = Precat-precious metal, main cat=ceramic 400cel
Cost = $3000 or $1200 used.
<img src="http://65.182.219.254/smokin_s4/RS4_DPs/images/DSCN1391.jpg">

<b>Tantrumwerks Split Downpipes</b>
Diameter = merge into a 2.5" pipe
Pre-Cats = NO
O2 Sensor location fore and aft of cats = YES
Test Pipes = yes
Flex Joints = YES (metal mesh/bellows-type)
Cat Type = ???
Cost = $1550 for stainless w/cats (other options available)
other note: divorced wastegate downpipes
<img src="http://www.tantrumwerks.com/images/s4dpt4.jpg">

<b>Autospeed</b>
Diameter = 3.0inch, tapers to 2.5 for most aftermarket cat-back exhausts
Pre-Cats = NO
O2 Sensor location fore and aft of cats = YES
Test Pipes = YES
Flex Joints = 3" Stainless Steel Braided Flex Joint.
Cat Type = 400cel ceramic cats
Cost = $1549.
<img src="http://www.autospeedperformance.com/Exhaust/dp.jpg">

<b>GHL Downpipes</b>
Diameter = 2.5
Pre-Cats = NO
O2 Sensor location fore and aft of cats = YES
Test Pipes = YES
Flex Joints = 3" Stainless Steel Braided Flex Joint.
Cat Type = ???
Cost = $1279
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