This project took me about 12 hours to do. I lost a lot of blood and made a thousand mistakes in the process. Hopefully this will help you along the way and not waste time and energy doing unnecessary steps.

Tools:
Car Jack
two jack stands (or ramps to get the car up)
wrenches in 10mm, 13mm, 14mm,
rachet and sockets in same sizes
Breaker bar
o2 sensor socket
Adjustable wrench



First of all, I want to thank all the members here who helped me with this:
Don (fstcrvs)
wspy
JCRDX11
ronrsx


Step 1

A day or two before I planned on doing the work I started spraying all the bolts down with wd-40 to loosen them. This included the 3 bolts behind the midpipe, two bolts at midpipe to Downpipe, three bolts at top of downpipe to turbo and various heatshield bolts.

After doing this for two days it did absolutely nothing. I then went and got some PB Blaster and sprayed it all over again. The two or three shots I did with this stuff did more than all the WD-40 I had done to that point. This set me back about half a day. The bolts will be rusted, use the best stuff first and don't waste you time. Don't forget to disconnect the neg battery terminal. Purely for safety, and make sure you have the radio security code handy.


Step 2

I took the intercooler off next. It is fairly straigh forward. If you can't figure how to do this part, then STOP, put your tools away and close the hood. This DIY is not for you.

Anyways. There are 4 10mm screws to undo. One in the front center, tow in back and one on the drivers side. Next, undo the two 10mm bolts holding the BOV on. This is located on the drivers front part of the IC. One is ver hard to get, be careful you dont drop it down in the bay.

Now there are two pipes you need to undo. Again, 10mm or phillips head screwdriver will loosen these hose clamps. one in front to the TB. I undid the entire thing and took it off the car. The pipe in back I just loosened the top clamp and pryed the IC off.


Step 3

Next I jacked up the front wheels and put them on jack stands. I only got aobut an extra 4 inches of room, but it certainly helped. I got under the car and took off the three rear screws off the back of the midpipe. I believe these are 13mm bolts. Then I took off the two 10mm spring bolts off the downpipe and slid the pipe off the hanger. After letting the PB blaster do the work this was relatively easy. At this time I used my o2 sensor socket (one with a slit up the side) to remove the 02 senor at the bottom of the DP. with the heat shields in place you will need this tool. Otherwise you will have to get the heat shields off before you remove it.


Step 4

There are two heat shields I removed. From the bottom, there is a large one on the right hand side of the downpipe. Two 10mm bolts hold it in. I wiggled it around a bit and did some bending before sliding it out the back of the sub-frame.

The second heat shield is on top in front of the downpipe attached to the engine block. Again, two 10mm bolts holds it in. Just run your hand back there and you will feel them. At this time I used an adjustable wrench to remove the A/F sensor a the top back part of the DP.


Step 5

From both top and bottom start removing all the 10mm bolts that holds the heat shields to the cat. Most of them you can get from the bottom. I could not get to all of them so I removed the cat (next step) and manipulated it in the small area to get to more bolts.

Doing this I stripped a bolt. I got the dremel out and spent 30 minutes dremeling the entore bolt/scre area out to remove the heat shield.


Step 6

Remove the two 14 mm bolts from the top and back of the downpipe. The one closest to the fron tof the engine located down below (just out of sight) is actually a bolt. After a combination of wrench and rachet I learned it was a bolt as it dropped into the abyss of the engine bay. an our later and a flashlight claw it was retrieved.


Step 7

Remove downpipe. Not as easy as it seems. Althoug I was told you can only manipulate it from the bottom of the cup up and out I was able to pull it up through the top by being on top of the car. I turned the opening of the downpipe towards the front of the car and snaked it out. Much easier said than done.

Step Eight

Now, after having all the pieces out it was time for me to do some work. I did not buy the midpipe. Being an Audi guy I an familiar with gutting cats. (car version) I took the midpipe and help it up as seen below.

You can use any solid piece that is at least a foot long and smash it into the cat. Make sure you hit all the sides then just dump all the pieces out.

I then washed the pipe out with water just to make sure it was clean and BAM! Spotless.

This took me about 15 minutes max. saved me $300 and fits like a glove.

I then took the DP and midpipe and cut a gasted to fit between them. Instead of buying one I just bought some gasket material at a car store for $10 and stenciled out two gaskets.

I cut them out, put a little oil on them to "seal" them together and test fitted them between the pipes. I figured twice as thick would be better to seal the two ends together. This would be a good spot for a leak and those are both annoying and a pain to fix.


Step 8

Install
Before installing the new downpipe I put the two heat shields from the engine bay back in. Next was the downpipe. First I added the A/f sensor and tighten it down. I got a new gasket online and put it on the turbo outlet, downpipe on around the lower bolt and screw on the other 14mm bolts.


Step 9

Back under the car I re-installed the o2 sensor and tightened it down good. I slid the midpipe back on and put the nuts on a few threads so I can move the pipe around. I picked up two 1.5" bolts/washers/nuts ffom HD and put the gaskets on the midpipe and bolted the downpipe up. After tightening that the bst I could I put the hanger back on the midpipe.

A once over of all the bolts underneath and I slid out from under the car.


Step 10

Taking the car off the jacks, I put the intercooler back on in reverse, bolted up the the BOV and snapped on the cover.

A quick wash and turn of the key and drive.

Good luck! I ran out of time so I will be adding/editing with pictures and more details when I get a chance.

 

Great stuff Matt, awaiting pics!

 

Plus 1!

 

Matt,

Is the 02 sensor above the primary cat media or below the cat media? I was thinking about doing the same procedure but gutting the primary cat rather that putting on the DP. Per your advice and pics (many thanks) I gutted the mid-pipe without incident. Also, is the primary cat filled with the same stuff as the mid-pipe?

Thanks in advance for your response.

Dan