fuel prblems

well my car drives ok at low rpms 1000-2000 after taht it starts to studder and shake and all the great **** so i went and got codes pulled and it said fuel circuit malfunction does anyone know what this could possibly be ...
iv got brand new cap and rotor and plugs and all the stuff
 
i just had a similar problem. i would start by checking the fuel pressure. it should be around 39 psi. if its low an upgrade might be in order. if you do change the pump spend an extra 5 min and 10 dollars for a filter. the second thing is the EGR valve. i was trying to replace the regulater (which rarely goes bad) and to get to it i took off the egr just to see that it was corroded and wouldnt open or close. all it took was some carb cleaner and a rag and it was back in action. running as good as ever. good luck
 
What codes? Specific code numbers are need to get you a useful answer. Without the code numbers, it is just a poker game guess as to what the problem really is.