Description: These are Sold Individually. 4 cylinder. S-series. 2.8l. S-series. 2.2l. Cavalier. 2.2l. Sunfire. 2.2l. Helps provide a leak-free seal Allows exhaust pollutants to enter the engine for re-burn Helps the engine emission system operate properly This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors