sauliux20

Hi, I am new to forum. I bought lexus is220SE 06reg half a year ago and already had a lot of problems.. Car done 112000miles. Has part lexus history. Here is another major problem. Car keeps jumping into limp mode intermittently, some times with P0093(large fuel leak detected) fault code, but sometimes with P0088(too high pressure in common rail). Two diesel specialist garages could not find anything. Had fuel pressure sensor and fuel discharge valve changed on common rail. Intelligent tester II shows that everything is in normal order. Please help Is there any connections between P0093 and P0088 fault codes? Could it be suction control valve(on high pressure fuel pump)? Any ideas welcome.. Thanks