Shade tree mechanic looking for the help of people that know more than I (which is probably plenty of you). Car is blowing light colored smoke out the exhaust and running rough during idle and through RPM range. No CEL (I've got a OBD II reader). I assumed head gasket, but compression is ~180 psi across all four cylinders. I've replaced the intake manifold gasket and pcv valve. Just because its easy, I also replaced thermostat, radiator cap, plugs and wires. I'm getting solid fuel pressure at the fuel rail and spark from all four plugs. I've checked for vacuum leaks as well as I could w/o a test gauge. I cleaned the fuel injectors and egr valve. I'm pretty much just throwing stuff at the wall at this point. Where do I go from here with diagnosis? Could it still be head gasket and compression isn't telling me? Any help is very much appreciated.