The contact owns a 2014 GMC Terrain. The contact stated that the oil reservoir was constantly needing to be refilled. The contact stated that he had to have the oil changed and added every 4 weeks. The contact stated that the check engine warning light had been illuminated. The contact had taken the vehicle to an independent mechanic who diagnosed that the catalytic converter had failed due to engine oil deposits and needed to be replaced. The vehicle was repaired. The contact stated that the failure reoccurred, he saw the check engine warning light was illuminated and was again having to add oil due to excessive oil consumption. The vehicle was taken back to the same independent mechanic who advised that the catalytic converter was going to fail again due to oil deposits. The vehicle was not repaired. The manufacturer was informed of the failure and referred to the NHTSA Hotline. The failure mileage was approximately 160,000.