Yesterday the "Service Engine Soon" indicator light came on in my 2001 Nissan Sentra GXE. I went to AutoZone and the accessed the code. It was P1491. Looking on Google I found this description: "Vacuum Cut Valve Bypass Valve". The guy at AutoZone told me he erased the code since I wrote it down. That made the indicator go off. He said if it comes back then it is important. I only drove the car a couple blocks since then so I don't know if it will come back on.
The question is: does this sound serious? Should I take the car to Nissan anyway? Can a place like Pep Boys do this sort of repair.
Please note that AutoZone does this for free so you don't have to pay the dealer if the light come on because you failed to tighten the gas cap!