Update: Oddly I took the J shaped Vibrant O2 spacers off and used some straight spacers that were given to me with the test pipe. Since using them, no check engine light. No need to switch tunes, now. 

With the new custom test pipes and catted down pipes, the O2 spacers I got just aren't cutting it. I got some different kind O2 spacers on order, but I fear I'm always going to have issues with the Check Engine Light (CEL). Sadly my current tune with EPL doesn't offer a "test pipe" tune. I really do love the burble and soft crackle you get with the new adjustable tune they just released. While they have been nothing but super helpful, I feel like my options are limited here. Honestly, I could just go cheap and put a sticker over the CEL and call it good, but then I can't visually know when there is another problem. This also applies when the CEL is always on, unless you go check for errors you don't know when faults start adding up. The 3.0l is a pretty reliable engine so it's not like 2.7t where you might have a CEL on so much that it burns out the cluster bulb. I typically scan for errors once a month via my OBDeleven, but I really like to keep my car running as problem free as possible.

That all said, I know the current battle on the B8 S4 platform has been IE vs 034, but as of lately I've heard more good things from from 034 customers than IE. Also I've really enjoyed the transparency and info 034 offers on their Youtube channel: https://www.youtube.com/user/034motorsport/videos

I'm going to reach out to them to make sure they offer a "test pipe" tune, and hopefully in the coming months make this CEL go away. If you run 034, please comment on your thoughts. Thanks all!

Wait what? Let me explain. So I was looking at the old supercharger pulley and took some measurements and it is nearly same size as the pulley I put on. (Little over 57.5-57.7mm depending on where I measure it). I know this is smaller than stock so this means one of the previous owners had a stage 2 tune on this car. Also when I went to stage 1 I noticed a major hit in my MPG as my car was likely running too lean as the supercharge was spinning faster that stock and blowing the air to fuel ratio out of whack. I think the previous owner likely flashed it back to stock as the stock tune would be able adjust for the different boost from the supercharger, it just the stage 1 was not designed for the pulley to be there so that likely where the problem is. I'm going to give the stage 2 tune a few tank fulls to see if now my MPG comes back up.

That all said, I did look over my install pictures and the car itself and sadly I can't find any other major upgrades that I should be aware. I was really hoping to find the crank pulley and cooling upgraded, but it wasn't. The real question is what tune was on this car before? I've emailed all the major tuner and gave them my VIN to see I can find who it was. Kind of a shot in the dark if any of them reply. 

As for the EPL Stage 2 single pulley tune, it certainly has a lot more low in torque and generally more power along the full range. It is simply stupid easy to break loose my all season tires on a slightly wet road with traction control set to off. I'm ditching these tires went spring comes as I'm getting winter tires install this weekend and hope to run summer tires next post winter. As for the tune I'm happy with it. I've very interested to see if my MPG improve now that everything is back in sync. Only time will tell...

First off, I bought this tune, with my own $$$, so take note this is not some hidden sponsored blog post. I ordered the Stage 1 tune, and had the software and first revision of the tune within a few days. They do ask for all your modifications so they can prepare the tune as the cable is getting shipped out. You log into their online portal, download their software and download your first tune. With the OBDII cable provided, you connected it to the OBDII port and your PC. Getting the PC and OBDII to connect can be a little fussy some times. If you are a computer nerd such as myself take note that using a USB over serial type connection like this cables can require a reboot of the PC when things to don't work. So for laptop users that just leave their computer in standby mode, reboot and then connect everything to reduce connection errors. That said, you first "Read the ECU" to save a copy of your current ECU setup. As I didn't know what I was running, I really didn't care about that, but did it anyway. After that, to Write to the ECU you locate your tune file that your previously download and get ready to write. You will get warning that it is best to have a charger connected to your battery. I risked it and didn't do that, but I turned off all lights, radio, AC/blower, etc so there was little to no draw. The writing process takes about 5-10 mins from start to finish. Once it was done I disconnected and then connected vcds to do a throttle body adaption. This was not requested by Motoza, but I did it anyway as many forum members recommended it after loading any kind of tune or resetting the ECU. After that I went for a drive for about 20-30 mins to get the S4 nice and warmed up. After it was warm you enable logging via their same software with your laptop and the supplied OBDII cable. They recommend to log for 15+ min to get a good sense of how the car is doing. Do a couple of WOT runs, cruise on the highway, and some city driving. After the logging, you upload the log files to the same online portal. 24-48hrs later they review the logs and provide a new tune revision if one is needed. When I got my second revision, I did the same thing write, log, and report my experience. Currently I'm waiting on my last revision as we are going to bump up the boost a little more. Currently we are peaking at 20psi at WOT so I'm interest to see what this 3rd tune will feel like. They have been very clear that doing this little extra with the boost is likely going to reduce the life of the turbos. If the k03 die, I guess I'm forced to upgrade. Oh darn.

How does this tune feel?
Simply great! I drove from Seattle to Leavenworth, WA and back and had a 27mpg average while doing 65+ mph pull most of the way. My S4 pulls hard for being on KO3... harder than it ever has. Keep in mind that I have APR tune and a MTM tune, all I can say is this Motoza tune is heads and tails better than any of the others. Which is not shocking as must S4 owners will say custom tunes are always going to be better than "tune templates" like what is offer by GIAC or APR. The simply fact that is custom to my setup is really bring my S4 back to life. 

Whats Next?
Well Motoza offers a Stage 1+ upgrade, but it requires using 550 CC injectors, but the tune itself is only $40 upgrade. I could do a E85 tune if I wanted, but there is little to no E85 stations around the Seattle area.  So I'm out of luck with that. I think I'll get the 550 CC injectors later this summer and do the Stage 1+ upgrade. This should pump out another 20-40 more HP and 10-20 ft-lb of torque. Nothing huge, but it does prepare me for future K04 or other hybrid turbos. 

In Summary, if you looking for a new tune, or maybe you were in my boat and didn't know what tune you were running, I can't recommend enough about Motoza Performance. The tune is impressive and the service and support and honestly the best I've ever experienced ever in my life. And best yet the price is hard to beat. 

Link: ​http://motozaperformance.com/product-category/software/audi/audi-s4/b5-2-7t/
Price: $349 (as of June 2018)