Why would a check engine light come and go? When it's on it checks out as a knock sensor. Also, the brake light is similar, but I can occasionly turn it off by using the handbrake. ....
Intermittent dashboard lights on 2001 Subaru Outback
by MzPat in Bridgeport, CT on February 24, 2011
ANSWER by overbys , February 25, 2011
the check engine light comes on whenever there is an engine management system failure. you can either repair that problem or you can ignore it.