The car runs fine but will stall for no apparent reason. Customer has already replace the TPS, MAF, IAC, 1 of the coils and the Ignition Control Module. The MAP appears to have been replaced at one time as well. Fuel pressure is at 44psi (should be 40-47psi) and when car is started stays at a steady 40psi, when I removed the vacuum line from the regulator pressure went up to 50psi steady. While looking at the live data everything looks just as it should. He replaced the fuel filter last year also. While I was getting it hooked up it did quit 2 times so I did not get to see what was going on, after I got it all hooked up it kept running. Since the fuel pump is running fine and since I have never seen an electric fuel pump quit working then start working and I have absolutely no codes I am thinking that there may be something wrong with the fuel pressure regulator.