Canada Tax Questions Answered by Experts
Your post is a little confusing as you say you left and owe but then you say you tried to file a few times.
If you filed and just did not pay then you can do that now by following the link belowhttp://www.cra-arc.gc.ca/mkpymnt-eng.html
If you truly never filed then you need to do that first. Then you can file a disclosure statement. The disclosure is made on form RC199. If CRA accepts your voluntary disclosure, you may only be charged the taxes owed plus the interest, with no penalties.