Sometimes my thermopride furnace kicks out smoke out of the front near transformer and also get smell out of register. Have tried having it cleaned but no dice.

It is time for you to call for a on site burner tuneup by a professional who is used to dealing with oil burners. The tune up will probably cure the puff back/delayed ignition but I also suggest they check the heat exchanger while they are there. Thermopride probably makes the best oil furnace in the USA but they need to be professionally serviced and that should be done once a year.

This seems to be the worst after the furnace shuts off. This furnace was cleaned and serviced in march or April and it did the same thing afterwards.there is an extra entrance hole on chimney pipe outside where there used to be a woodstove hookup that is not used, could that be causing some type of backdraft when furnace shuts off and there is nothing going up chimney pipe?

There is an extra entrance hole on chimney pipe outside where there used to be a woodstove hookup that is not used, could that be causing some type of backdraft when furnace shuts off and there is nothing going up chimney pipe?If the hole is open, the inside flue draft will be weak. Close it up if it isn't already.