Its been three years that i had my nose job done, and since that, my nose is always oily and i have black heads.whats the reason and solution pls.

Increased oil gland : This is due to increased oil gland activity partially due to the denervation of the skin. I am not sure anything can be done other than skin care with the possible use of topical retinoids, sunscreen, exfoliation, comedones extraction, benzoyl peroxide and gentle cleansings.

Skin care regimen: You may need a better skin care regimen. A rhinoplasty (or nose job surgery) alone is generally not the culprit when it comes to skin problems. Best to see your plastic surgeon or dermatologist for more information.

Unrelated: Skin changes 3 years after surgery are probably not related to surgery. See a dermatologist.

Blackheads: The skin issues you describe may not be related to your rhinoplasty, especially at this point. Have your skin evaluated by a board certified dermatologist.