I have a 420a eclipse and it is running like crap. When I take off in 1st gear it stumbles quite a bit and sometimes almost dies when it idles.Also when I floor it it takes forever now to get to 6500 rpms.I had my cousin do a fuel pressure test on it and it held pressure at idle, but when I turned the car off the pressure dropped to less than 30psi in under a minute.I have an Obx 4-1 header,CAI,Obx intake manifold,55mm throttle body,and no catalytic converter. I have not been able to figure out what the problem is, so any input will be much appreciated. Thanks

u should not be running a test pipe if your n/a . you want backpressure n/a . maybe thats why its falling flat at high rpms

Thanks for the info. I am going to look in to getting a high flow cat when I get the money.