ya, my 1st guess would be boost leaks, when you 100% sure that not it, the only issues would be either your wastegate will not hold the boost, or your bov wont. it could be either, and i have heard horror stories from both. me personally i had trouble out of the greddy rs more than the wastegate, but when you can afford to i would replace both. start off by putting the factory uppipe etc back on. if that fixes the prob you know its the bov. if not you can ref-attachyour bov and replace the wastegate