My car is a 2000 gt with a saleen series 2 supercharger and intercooler, bassini x pipe, among many other upgrades. Lately the car will be idling just fine and then will drop down around 500 rpms and some times just cut out and die on me. It is driving me insane!! A trouble code has come up and it reads p0401. Which is an "insufficent egr flow". I have changed out the egr valve with no luck. I have also inspected the egr line and it seems to be sealed. I need some serious help here as I have exhausted all of the possibilities that I know of. Thanks in advance for the input... Also, there is a leak in the exhaust manifold on the passenger side that I haven't fixed yet... I really don't think this would play into it, but just a little fyi.