Subaru Repair: 98 Forester check engine light, input sensor, noticeable problems

Question
The suby was checked out at auto zone and the code was said to be the knock sensor.  Should this be replaced and
about how much do they cost?  The light went off for about a day then has since come back on. Hummmm?  

Answer
The knock sensor is a major input sensor for the computer to use to control engine timing. So, yes it should be replaced. But, if you need to put it off for awhile, I dont think you will have any noticeable problems. The sensor lists for $94.17 from Subaru, and about $65.00 for the labor to recheck the code, replace the part, and clear the code afterwards. Also, if you like to work on things, it is not a hard part to replace. Good luck, Z