Excess smoke typically indicates a problem with:
Blocked vents and airways prevent smoke from escaping. Clear all vents.
The door gasket is damaged and smoke is leaking out. Replace the worn gasket.
Grease build-up. Thoroughly clean the oven, including the ducts and fans, to remove grease.
Burning of food residues due to insufficient cleaning. Wipe the inside with an oven cleaner.
Worn catalyst on gas ovens. The catalyst may need to be replaced by a specialist.