August 9, 2004A couple weeks ago my service engine soon light came on. I took it to my bosses dads shop for him to look at it. It had a clogged fuel filter and and an 02 sensor went bad. NOw its a week later and the light comes and goes off sometimes. I went back once and the computer said it picked up a richness in the fuel to air mix. What could cause this? They also did a fuel system flush.