I don't actually know the code, but I know my mechanic had to wire it
up to blink out the codes manually because he tried like 9 readers and
none of them would pull the code. But the exhaust was replaced because
my catalytic converter was toast (you could hear the crap inside
rattling) and the belt was the original after 125,000 miles. The
mechanic isn't jerking me around as far as I know, but I am planning on
returning to him soon (he promised to give a reduced charge if the
light came back) I'll suggest checking the O2 sensor/wires and the PCV
valve which I read somewhere else on this group might cause this.