5000 qt probs

[ScottyCBoy@aol.com]

Hey guys,

     My 5000 is behaving rather weird.  When I'm driving down the road at
light throttle about 55 mph or so the engine light comes on.  An on occasions
when I get up on it the light comes on again.  This occurs about once a week
for about two days.  When I chack codes on the fault memory I get a maximum
retard code.  The only other thing I've noticed is that when it does this the
lifters make nosie at low RPM >2000.  Could a lifter mimic a gas knock??
 What other things could it be?? Any BTDTs would be greatly appreciated...

Thanks,
Scott