Today is the day I get my S4 back. Michael at Apex Performance and Fabrication (also found on Facebook here) just sent me these pictures last night.... and all I can say is WOW, just amazing work. If you live in the PNW and need exhaust or other fabrication (they do lots of stuff) I certainly recommend this place.  

• Catalytic Converters used: MagnaFlow 53956 (affiliate link)

My initial thoughts of the sound? Yes it has some rasp, but the more I drive the more that seems to go away. So far I think I've put many 100-200 miles on it (video is showing zero miles) since I got the car back and every heat cycle the tone has gotten lower and less raspy. I will say this is much louder then before, I'm a little undecided if I like it or if I need to add some resonators back to it. Likely in a month or so we will have true idea of the sound and a update video to follow. Subscribe to my YouTube channel here.

 - Amazon affiliate links were used in this post

Well my passenger side cat (catalytic converter) cracked right before the flange that connects to the headers. It all happened when I would pulling away kind of hard from a intersection, heard a pop, and the car immediately sounded bad. Drove about 5miles home and captures this video of just how bad it sounds.  My guess is that during our snow storm about a week below that I hit some deep snow and it caused too much flex on the exhaust. Likely formed a crack at that point and just blew when I pushed the car hard. Oh well I knew I would going to need to do something with the cats if I ever wanted to go dual pulley. 

And just for reference this is how it sounded days before when I flashed the latest EPL tune update:

I had the S4 towed over to a Apex Performance & Fabrication. The plan is to take out the old cats, fab a test pipe from the header to the down pipes... and finish with new cats in a newly fabricated down pipe. The owner explained to me there is no point in trying to re-weld the old cats as they will just crack again. And we all know this is a common problem in this platform so that was no surprise. Anyway that is where it is now I will post again with some more videos of the sound changes (if any) once I get the car back. 

Following some of the suggestions found on the following thread, I decided to modify my existing stock exhaust to allow it to sing a better tune. 

https://www.audizine.com/forum/showthread.php/406948-Exhaust-Mod-Resonator-replaced-w-X-Pipe-(video)

So, I had a Magnaflow 11385 installed where the baby resonators are located, and straight piping where the mid muffler.

And here is a drive by, drive away, inside, and some reving all in one:

​As for my initial thoughts, it is near stock like quiet when cruising at 60 mph, no drone at all. Once you open it up it has a prrr like sound very familiar to a VR6 or VW R32 with out the the lower tones. The best part, if you drive it gently, it really is not much louder than stock. Not to mention from the outside, it still looks 100% stock.

Found this key fob from a post on Audizine and purchased off eBay. Works great except the trunk button doesn't do anything. I'm just glad i finally have a spare set of keys.... only took me 9 years to get another fob. Just for the record, the B5 line does not use a "immobilizer chip", so if you get one of these, don't get suckered into paying for that to be "programmed". The locksmith I went to get the key cut was convinced it would not work, but I got to show him that he was wrong.  

• Audizine Thread: https://goo.gl/j4mMpH 
• eBay Link: http://www.ebay.com/itm/131224505466
• Audi Sticker: https://amzn.to/2q9ouKR

And a little videos to show it really works:

Before you start, make sure you have at least two keys that can manually unlock/lock your car. You can not program your key fob with only one key.

Clear your Key Fob Memory Positions
Our B5 S4 can store up to four key fobs for wireless entry, but to simplify the process of programming it best to start with a clean slate.

1. With one key fob, insert the key into the ignition and turn to the "on" position. Take note we are not turning the engine on, just the one position.
   
   
2. Exit your S4, close the door, and insert your second key fob into the door lock.
   
   
3. Turn and hold your key clockwise to "lock" you car.
   
   
4. While still turning the key to the lock position, press the unlock button on your key fob 5 times. Wait one second between each press.
   
   
5. Wait 5-8 second, take your key out of the door and press the "unlock" button on the key fob once more. 
   
   
6. Open your door, take your key out of the ignition, and verify all key fobs no longer wirelessly lock/unlock your S4.

Re-programming your New and Old Key Fob.

1. With one key fob, insert the key into the ignition and turn to the "on" position. 
   
   
2. Exit your S4, close the driver door, and insert your second key fob into the door lock.
   
   
3. Turn your key to the lock position, hold, and press the unlock button just once.
   (This action initiate the key to be recorded to the 1st memory slot)
   
   
4. Take the key out of the door, wait 6-8 seconds and press the unlock button on the key fob once more.
   (This action will save/record the new key)
   
   
5. Open the door, take the key out of the ignition, and test the key that was previously in the door to make sure it wirelessly locks/unlocks.
   
   
6. Now we need to program the key that was previously in the ignition. Take the key that was in the door, insert into the ignition, and turn to the "on" position.
   
   
7. Close the driver door, and insert the other key fob into the door
   
   
8. Turn your key to the lock position, hold, and press the unlock button two times with a 1 second pause between each button press.
   (This action initiate the key to be recorded to the 2nd memory slot.)
   
   
9. Take the key out of the door, wait 5 second and press the unlock button on the key fob once more. 
   
   
10. Open the door, take the key out of the ignition, and test all of your key fobs.

Troubleshooting
When I first attempted this I noticed I could only get one remote working at a time. That is when I realized I was saving one key fob in the same memory slot. Take careful attention to step #3 and #8 as you are selecting which "memory slot" you are recording the key fob too. The number of times you press the unlock button will instructed which memory slot is used. 3 presses will go to memory slot #3 or a single press would go to memory slot #1. Remember, there is only 4 memory slots, so don't go crazy and press the unlock 5 or more times as that will clear all key fobs and you will have to start over. 

New picture with Audi logo