The contact owns a 2024 Ford Transit. The contact stated that while driving at various speeds; an abnormal fuel odor would leak into the interior cabin, which caused health issues. In addition, the contact stated that while stopped around other vehicles in daily traffic, the exterior exhaust fumes would leak into the interior cabin of the vehicle. No warning lights illuminated. The contact sought medical attention for vomiting and severe dehydration due to a high carbon monoxide poisoning level of 2.6 as a non-smoker. Upon further inspection, the contact noticed a leak on the passenger side manifold and under the flexing coupling. The vehicle was taken to 3 separate dealers, where the vehicle was declined to be diagnosed. The vehicle was then towed to a local dealer, where it was diagnosed; however, no failures were identified. The manufacturer was made aware of the failure. The failure mileage was approximately 12,000.