Complex sentence: In 1982, hoping to attract more passengers, RENFE added second-class carriages to the train formation, so the TEE requirements were no longer met, and the "Catalan Talgo" was downgraded to a normal Intercity service.
Split into simpler sentences: In 1982, hoping to attract more passengers, RENFE added second-class carriages to the train formation. As a result, the TEE requirement of first-class-only cars was no longer met, and the "Catalan Talgo" was downgraded to a normal Intercity service.