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 on 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.