I got an 06 WRX several months back, my firs Suby ever, and am loving almost everything about it. It came with a few mods: HKS BOV, HKS TBE, triple gauge A-pillar pod, carbon fiber hood, and fiberglass trunk lid. The only problem I'm having is that the car runs rich and backfires. I also noticed a puff of black smoke from the exhaust during hard acceleration the other day. To my knowledge the ECU hasn't been tuned, but I can't be sure. Any help would be appreciated.