Cat-less Downpipe and turbo back with no EM
So I have barely had my car as I bought it on Christmas Eve. After driving around for awhile I've decided I need some type of Engine Management to help my car out. It is a 2002 Wrx Wagon with a Catless everything, Uppipe, downpipe, and turbo back. It runs and sounds nice when not at idle. At idle the exhaust is a little distorted and gives an in and out sound if that makes any sense. It will sound better for a couple seconds then go back to muffled, then to clear. I'm pretty sure I'm getting CELs from the O2 sensor but I still need to get those checked. And I think the rough idle is caused by my unhappy CPU. Right now I'm assuming its only the O2 sensor because everything else it doing pretty well. I don't believe I have anymore vacuum leaks because I'm hitting full boost and holding a better idle pressure. I'm looking at getting an Accessport v3 for my car and use a stage 2 tune. If I go this route I'll probably upgrade my air filter, change spark plugs(going to do anyway). I've also been looking at Open Source tuning and it is almost looking like a better option for my car, I have a laptop and I am really good with technology.... Just not sure what to try and do at this point. Should I save up for the AP or go with OpenSource tuning. And just some FYIs, I don't want to make a ton of power, I just want the car to run a little better because I feel like the mods are throwing the ECU off, the car has a little over 202,000 miles, Transmission was a needle in a haystack, but I found a really good one. Just don't want to push the engine at this high of miles. I would be ok with the Stage 2 boost levels though. Just don't want to do something I'll regret.