So here I go. Have 2K4 WRX. Drove it around a little this morning and no problems. Went to go to the store, started it up and started to back up and white smoke came out of the exhaust. None at idle just when reving up. Checked the oil and was about 3/4 qt. low. Added oil. Checked coolant res. and saw nothing unusual. Drove it a few blocks, revved it up a few times and alas no smoke. Hooked up COBB AP to see where the boost was at. Displayed a high of 13. Normally 14.5-14.7. And no longer sounds like a banshee when spooling up.