90 days ( GOOD ) - this selection is chosen most by used car dealerships, individuals that are not expecting to keep their vehicles, or budget minded individuals. The item is still constructed from top quality materials, simply discounted to reflect the limited warranty period and offer the customer the lowest possible price. Converters with this warranty are still constructed using OBD2 cores to ensure no premature check engine light and what the market would refer to as a standard grade OBD2 unit. ALL grades feature stainless flex connectors ( if applicable) , stainless converter bodies, and stainless o2 sensor bushings.