My check engine light has ben on for a couple of months now.  I took the car
to get it inspected and they told me it is an automatic failure because of
the CEL.  I took the car to a mechanic and he said that the air intakes are
clogged with Carbon.  He said that he is going to clean them out and replace
the valve associated with it.  Cost $800.  I asked him if he would go ahead
and inspect it after the fix.  He said I had to drive the car for 100 miles
or so for the fix to register and pass inspection.  Does that sound right?  I
know nothing about cars.