No way!! They're just trying to make some more $$. You can just buy any quality bellmouth DP and catback and that will work fine. Then to make it even better you can do the uppipe and intercooler hoses. The hoses won't make as much of a difference as the uppipe.
Since you have to take the DP off to do the uppipe you may as well do it all at once. My suggestion would be to find someone selling they're exhuast and have someone in your local area help you install it. Its not that bad especially if you're not doing the uppipe. If you wanna to the uppipe make sure to get someone whos done it before to help.
Then just flash your Stg 2 base map and realtime map with the AP and enjoy.
Q. What is needed for Stage 2?
A. We actually field a lot of calls with people wanting the Stage 2 AccessECU because the dyno graph looks a lot better, but they do not have a turbo-back exhaust. Here is a diagram of the exhaust to help you visualize:
The Stage 2 was tuned on a car with a full turbo-back system. If you have pieced together a less than optimal combo of parts or those that were not designed to work together you may not get the full benefits of the Stage 2 AccessECU. Boost may not come on as quickly and the peak power may be down from those that have a well designed full turbo-back system. If you have replaced the first section (second cat or downpipe section) and nothing else, then the Stage 2 map is what we would recommend. Again the results will be far less than optimal, but it will control the boost better than the Stage 1. If you have replaced sections 2-4 (third cat, mid-pipe, and muffler section then you are still Stage 1. You managed to get all except the part that makes the most difference. Again, we want to reiterate that Stage 2 will only get the intended results with a well designed complete turbo-back.
Q. I have an up-pipe, and/or intercooler hoses, and/or a panel filter, and/or a BOV, and/or pulleys, etc. but I donít see a map with those mods. What can I do?
A. Those types of modifications are within the AccessECUís ability to adapt. Most of them (with the exception of the BOV) make a slight improvement in efficiency, but do not change the characteristics of the car enough to require reprogramming to work properly. If you add these types of parts later it might take the car a driving cycle or two to get the boost right on, but it will likely adapt unless the part makes a significant change such as a turbo-back. As stated above, if you have a question about your parts, let us know and we will help you choose the map that is right for you. That is much better than getting a wrong map, or thinking we do not have a map for your combo.