One problem related to emission control has been reported for the 2005 Cadillac STS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Cadillac STS based on all problems reported for the 2005 STS.
Purchased a new vehicle that had an odd smell, but soon became overpowered with its strong odor. Consumer's wife eyes watered from the smell and her throat burned. Took vehicle to dealer for who tried to remedy the problem by placing odor eaters inside of the trunk from where the smell was strongest. The odor was stronger when vehicle was outside in heat or hot weather. Consumer was concerned that this may be toxic. The problem was ongoing. Contacted gm , but they did not answer the concerns. Vehicle continued to smell of odors. Front passenger side seat was squeaking with side to side motion. Front seat adjuster assembly replaced.