Oil smoke (blue) or coolant smoke (white) will not cause your vehicle to fail emissions test. If you have Fuel Smoke (Black) this will fail you. This is caused by a rich running condition.
First place to start would be a complete tune up and if there is a check engine light on, have necessary repairs made to turn light off.
If this is a carburetor engine, you may also need to have the carburetor tuned and the ignition timing set.
No need to worry about the smoke if it isn't black.
