The 2001 Chevy Tracker's O2 sensors ought to be found when the exhaust system. The Tracker employS3 sensors complete,with sensor 1 introduced in the ventilation system,number 2 preceding the feline and number 3 after the converter. They structure a significant connection in a vehicle's discharge and start frameworks by observing how much unburnt oxygen leaving the exhaust pipes. This information is shipped off the Tracker's primary PC and used to illuminate the motor's air/fuELRatio. While working,an O2 sensor assists with keeping up with ideal mileage and terminating. At the point when sensors begin to fizzle or become d***y,readings will be compromised,making the vehicle run as well "rich" or as well "lean" and can bring about unpleasant standing by,decreased gas mileage and mIS Fires.