One problem related to emission control has been reported for the 2001 GMC Sonoma. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 GMC Sonoma based on all problems reported for the 2001 Sonoma.
2001 GMC Sonoma sls. Started in may 2006 with 52,449 miles on vehicle: service engine soon light came on. Dealer identified bad O2 sensor and replaced ($253). Two weeks later at 53,131, ses light again. Dealer installed new check valve ($116). 3-4 weeks later at 53,892, ses light again. Dealer said water in air pump, replaced air pump and hose ($357). Now on 26 Aug (54,084) ses light just came on again. In 60 days, the light has been cleared & reset 3 times with over $700 in repairs and now another trouble.