Subaru Repair: blue smoke, subaru impreza, leavel

Question
i have a 2006 jap imported subaru impreza spec c
the car has been remapped for the right fuel.
last night as i was driving up a hill i noticed a lot of smoke from the rear of the car so i pulled over and reved it slightly and it seamed to be a light blue smoke but not a lot , as i drove the subaru to my house there was no smoke after that! it was only a 8 min drive, so i left the subaru in my garage and had a good look at it today, checked the oil and it was spot on the leavel did a few other checks and everything was ok, so i took it out for a drive no probs till i got to the same hill and i noticed light blue smoke as i was going up the hill again not as much as lastnight but still inuff to know there is sumt wrong. as i drive now i am looking very hard to see if i can see blue smoke while driving and the odd now and again i can but only a bit, but it seams nearly every time i go up a hill in low revs there is blue smoke when i go up in higher revs i cant see it! but that might be with the speed i am going! ther is no blue smoke on start up or idel or on when i warm the car up and warm the car down, no smoke on idel after a long drive ,short drive or hard drive , just on load up a hill in low revs? any ideas please?

Answer
There are a lot of possibilities and even though its been remapped it doesn't mean its right.A gas analyzer should be used to see the over all engine exhaust gas readings.Blue smoke is usually oil and it only takes a drop in the exhaust to make a cloud of smoke out of the tailpipe.How old is the oil ,if it is contaminated with fuel it will be more susceptible to burning.Sorry but there is a limit to what i can do over the Internet.

Justin
All Wheel Drive Auto