Describe: Condition:100% Brand New sensors measure engine vibration caused by pre-ignition When not replaced, vehicle may experience engine ping or knock, high emissions, poor fuel economy, internal engine damage and/or CEL/MIL illumination Fitment: Make Model Year Engine For GMC For Sierra 1500 2002-2007 5.3L V8 For GMC For Sierra 3500 2004-2007 6.0L V8 For GMC For Yukon 2004-2007 5.3L V8 For Chevrolet .