About a month ago I did a bunch of stuff to fix all sorts of problems (valve cover, PCV hose, and more). For that work I borrowed a code reader so I could reset codes and verify fixes. One thing that got replaced was one ignition coil. Roll forward to this week, I got a CEL & had Autozone pull it. Two actually P0302 & P0304. I figured, more ignition coils (120K miles), so just finish them out. Bought 3, installed, performace is back.

The question: Will the CEL reset on its own or do I need to go borrow the reader again just to reset them? I know some codes will go away, some won't. I've got about 45 miles on the new coils.

TIA

 

You may want to invest is a cheap code reader that read and clear codes. I got something called a U480 reader from Amazon for about CDN$22. It's invaluable for narrowing down code faults and resetting the check engine light.