Whiteish smoke coming from tail pipe!

I doubt that it will be a converter, but if you go get an exhaust gas analyzer test done this will show the emissions and give an indication as to the serviceability of the converter, also with the exhaust cold, just give the converter a thump with your fist, if it rattles at all, this will be an indication that the matrix has cracked.

White smoke is a sign of coolant burning, it may not be a lot and not very noticeable in the coolant, a head check will confirm this, this is a simple chemical test for Co in the cooling system, any work shop should be able to do this simple test, as for the exhaust test many work shops have 5 gas analyzers for general service work, ring around you should find one that can do this for you.