It's been a busy month so far with the S4. I did just finished installing the 2.0T Coil Conversion ​kit I got from ECS Tuning.

Performance Differences? 
In summary, no, not really. It kind of feel smoother when accelerating past 4000rpm to redline. I did replace my spark plugs at the same time, so whatever I feel could simply be fresh plugs. The good news is I'm able to run a larger gap with my spark plugs. I left them at the stock 0.028 inch gap and no misfires. Before if I ran anything over 0.024 inches I would get misfires in cylinder 6 at WOT. MPG does seem to be 1-2mpg higher as my 30min test drive on the highway shows 27-29 MPG. Again this could just be the news spark plugs. I do continue to feel slight shudder every 5-10 seconds when the car is at idle, but I have a feeling this is likely because of a vacuum leak around my intake boot.

(WOT = Wide Open Throttle)

Thoughts on the kit?
It certainly feels over priced and I knew that from the start, I just didn't want to deal with making a wiring harness from scratch... So yes, I'm paying extra from convenience. As well, the extra wiring kind of makes the engine bay look messy. I'm sure with a few black zip ties here and there I could clean it up, but I'll do that a few weeks from now once I'm confident that everything is working ok. I do really like the 1 piece mounting plate for each side of the engine. I pick the black color as I really don't like a flashy engine bay. The mount just look more OEM in one piece vs some other setups that have a separate mount for each cylinder. As for the wires they all look very OEM. The once thing I don't like is the length of the ground wire. It seems like it should be 1-2 inches longer so nothing is pulling on it. As the wiring is routed at this time, I'm sure a year from now I would be working on fixing broken ground wires.

How was the install itself?
ECS on their instructions claim this as a "easy install" and I do agree with that. The hardest part, as with everything on this S4, you spend more time moving stuff out of the way than you do with the actual installation of whatever part you are working on. Remove airbox, relocate coolant reservoir, remove old coils, install 6 bolt per mounting plate, press in the new coils, connect the wires, re-install airbox/coolant reservoir, and finally go for a test drive. So it's a rather easy install. I think it took my 2.5hrs to complete but I was going at slow pace.

Would I recommend it?
I would say that it is too early to tell. If you are bored and want to replace something with something "newer" because you got the itch... sure go for it. If your stock coils work without issue, then no, this would not be worth it for you. For me that cylinder 6 misfire is the main reason I replaced this as I wanted to see if it would help correct the misfires that seem to come back every 12-18 months. 

The S4 is back under the knife. Finally I'm getting my Power Slot Cryo Slotted Rotors and the  Akebono Ceramic brake pads all installed at I.P.M. Auto Services. Also my right rear bearing decides it was going into retirement so that is getting replaced. I just had the rear driver side replace 2 months ago, go figures. Rear Swaybar link are pretty shot so those are going to be replaced as well. And lately the bots that adjust the camber are likely going to need to be replaced. I can't remember the technical name of them but my right rear tire was maxed out and my last alignment Firestone could not get it perfectly in spec.

As for Coilpack conversion this has been something I've been following for a little while. As we all know the B5 S4 does not have the greatest record when it comes to our expensive Coils and ICM. I have been through 6 coil at this point. The great thing for this conversion is for one, you eliminate your ICM's. Keep in mind that if once of your ICM goes bad you are going to be misfiring on 3 cylinders as each ICM controls half the block. The 2.0t coils have them build into either coil, which cost $15-$25 each compared to the stock coils of $50-100 each. 

Also, the 2.0t coil have a easy twist on/off feature which makes replacing them extremely easy and insanely fast. And lastly they offer a much improved spark. Some Audizine users have said they have gapped their plugs up to .044" to experience a butter smooth idle and power delivery. No results on if this improves MPG but I have a feeling it likely will help maybe 1-2 mpg. To learn more about this conversion feel free to check out  http://www.audizine.com/forum/showthread.php/452609-Teaser-2-0T-Coil-packs.

I just learned that 034motorsport.com offer the complete kit, but it's a pretty big investment. I might be interested in getting the wiring from them but I'm still pricing around for the coils and checking if a local  machine shop could make the brackets if I can find the specs.

When driving home with my wife and 1 year old daughter I noticed some hesitation on normal acceleration. So I did a WOT in 2nd gear and man my car did not like that. It start to misfire really bad. So I continued on home and within 2 block of getting there I lost at least 90% of my power. I barely could get the car in the garage. My ScanGaugeII was not picking up any error code so that was not a good sign. Also, my car smelled like sulfur.

I call up my friend Erik that owns I.P.M. Auto Service here in Redmond and ask him if he could bring the Vag-com over. After a quick scan it showed that cylinder 6 was the only one misfiring. We took out the spark plug and it looked just fine. So we swapped in a old OEM coil pack that I had kept just in case. Fired up the S4 and it was running fine. First time I was able to get something fixed in under a hour and at no cost.

What's odd is that all of my coil packs were replaced 2 years ago/30,000 miles so they are not old at all. They are the Beru brand so maybe the quality is not that great. Hopefully the rest of them are ok and stay that way for a while.