Apr stage 1, Unitronic intake, cts turbo catless downpipe. Just had Sachs sre smfw clutch installed. 1 and 2 gear pull really well. Power delivery is very smooth. 3 hits and the exhaust makes a bogging noise as if it's trying to push power out but can't. R8 coil packs and ngk spark plugs were out in over last winter along with an o2 sensor on the turbo flange (cbfa engine). Getting the stage 2 update tomorrow. Any thoughts on what could be causing this? Car has 80k BTW