Engine Mechanical problem
2005 Chevy Silverado V8 Four Wheel Drive Automatic 147000 miles

Our 2005 Silverado 2500HD has been in for replacement of the OEM sensors. The codes state the heaters are bad. The sensors have been replaced twice and the check engine light continues to come on. The dealer can't seem to get this corrected. Is there a certain way to replace these sensors or something they are missing when doing the replacement (like resetting a code or something)? Thank you!