hesitation when accelerating
 

ive noticed a hesitation when accelerating and my check engine light is on for the secondary air injection system could this cause the hesitation and where would i start on fixing the problem i have a 2000 2 dr blazer 4.3 v6 4x4 also sometimes when tranny is shifting sometimes it sounds like its clicking in you can hear it as ur driving when the tranny shifts and sometimes it dont do it

*Moved to 2nd Gen Tech* - Please read the descriptions of the forum sections and choose the section that best applies to the nature of your question.

What is the specific code that is present? Have you inspected the AIR system for leaks? It is possible for the check valves to blow out and cause a rather large exhaust leak that can affect the O2 sensor readings, thereby affecting engine performance.