Just did a bunch of mods...ported manifold, throttle body, mafs, blaster coil, msd wires, champ plugs....and the car runs incredible, HOWEVER once it is warmed up, the idle begins to dip down to 500rpm or so, my oil pressure fluctuates, and registers as low as like 20 on the dash, it feels really rough, but as soon as you give it gas or reengage the clutch and take off, it recovers and drives fine. It has only actually died once, and whats odd is the car will at some point correct itself and jump back up to 1000rpm. My low oil light is on when cold, however i know my oil level is fine...probably just a sensor, but i cant figure out the idle??? Help!

 

Look at the fuel trims and O2 readings. Mine had a bad O2 harness and would think it's running rich when it actually wasn't. It would pull fuel until it bottomed out, jump to open loop momentarily. Run much better for a few seconds. Jump back to closed loop and start the same thing all over again.