Check Engine Lite is on on 2002 GMC Sonoma

What are the possible problems associated with the illumination of the Check Engine Lite.

Asked by for the 2002 GMC Sonoma
3 answers 1 comment
02 sensor front of catalytic converter or rear of converter.
Go to a Advance or Autozone parts house and ask them to code out the computer. Ask for the code numbers. e-mail me at swaths3644@mypacks.net
Can't help without a TROUBLE CODE
Check out these articles in the RepairPal Encyclopedia;
http://repairpal.com/check-engine-light
http://repairpal.com/check-engine-light-diagnostic-assistant