In 1966, Tennessee Gas was incorporated as Tenneco, Inc. Tenneco expanded into a number of business ventures as a result of diversification. In 1967, the company acquired Walker, Inc., a manufacturer of universal-fit exhaust mufflers and pipes. The year after, they started working on the construction of a universal-fit catalytic converter, that would become a cost-effective alternative to the OE catalytic converters. It took the company 8 years to introduce one. Tenneco bought Houston Oil & Minerals Corporation in the late 1970s. Tenneco owned and operated a large number of gasoline service stations, but all were closed or replaced with other brands by the mid-1990s.