went to advance auto today and they printed some codes out for me. i have a 1998 gmc jimmy and had the igntiion switch problem but the mechanic that fixed it forgot to clear the codes for the problems that come along with it would Advance auto clears these for free or no

 

Try unhooking neg. lead on Battery for a few mins.

 

Generally if the codes don't get cleared after being fixed by the mechanic, they will be erased after about 30 - 40 drive cycles with out another code for the same problem...just depends on the code and the fixed system...