I bought a 03 evo and it is running way too rich. At idle it will burn your eyes and under heavy throttle I can see black smoke in the rear view mirror. The car has a lot of work done on it from TurboTrix in NJ. Forged motor with port and polished head. Oversized valves with springs and retainers. HKS intake, Greddy BOV, 3" exhaust with test pipe. 255 fuel pump, 680cc injectors, HKS 272 cams and reflash. I called Trubotrix and he said I had a either a boost leak or vacuum leak. I can't find either. I'm getting a couple of codes. One of course is catalytic converter, the other is EGR flow but I found where the vacuum hose is just routed back to it so I'm assuming it has been bypassed altogether, the third is fuel pressure regulator control circuit. It is the stock FPR and fuel rail. Is the FPR my problem. The car idles like crap. It will idle well for a couple of seconds and sounds mean because of the cams but will slowly start to sputter then catch itself run ok and then start to sputter again. Any advice would be greatly appreciated. Is there a way to test the FPR? How do you test the fuel pressure on the this car?

 

ur idle condition sounds like u do have a vac leak.

u checked every single vac connection and hose for tears or rips? take a spray bottle w/ soapy water and spray it on ur vac hoses, look for bubbles.

also, zip tying vac hoses at their connections helps stupid vac problems from happening

 

Vacuum leak would not create bubbles, a boost leak would. You could spray soapy water to fill a leak momentarily which would stabilize your idle at least for the time it takes to suck in the soapy water.