One problem related to engine exhaust system has been reported for the 2001 Chevrolet Blazer. The most recently reported issues are listed below.
The electric smog pump on my 2001 chevy Blazer had failed when pump filled with water and shorted out. This is caused due to the short intake hose to the pump. This is an apparent known issue with gm, but they will not replace the pump. This also causes the vehicle to fail emissions testing. Gm wanted $400 for the pump + labor to repair the issue. Once the part became available for 3rd party vendors, we were able to replace the pump ourselves, added a longer intake hose, and the vehicle now runs correctly. I feel that since gm is aware of this issue and it adversely effects the emission control of the vehicle, the repair should be gm's responsibility.