It could be, have you check your fuel pressure when you driving, it must follow up whit your boost pressure. A friend of mine, got problem whit blocked fuel pipe, got lean on lambda on boost. After try everything from twin fuel pump, changing regulator, changing fuel filter, whitout help. Then we try whit a fuel pipe, and it sort it out.
Something blocked the pipe when rising fuel pressure, boost going up, and fuel pressure down, could make a melt down engine