OK Something Interesting happened on the way home from work tonight.

My odometer rolled over to 120,000 miles and the "Maintenance Req" Light popped on....

I went over the engine and fixed replaced everything I could except the Carb and the Timing belts.

I checked all the belts and they all look new. the timing cover was recently removed it seems as all the bolts were loose and one was hanging off but still attached to the spark plug separator....

So should I worry about this idiot light?
Does it come on arbitrarily once these trucks hit 120K?

BTW the truck runs and drives like a new truck .. well except for the exhaust leak noise.... LOL