Tire life depends on the maintenance, driving habits, and other factors of the specific
owner. You can have a 50,000 mile warrantied tire fail at 15,000 miles due to abuse,
and lack of proper maintenaince (checking the air pressure regularly), or ,as I had done,
have a 50,000 mile B.F.Goodrich All Terrain/TA tire go 78, 500 miles with proper maintenance
and air pressure checks!
Oh, and your original post... Yes, the I.A.C. valve is tricky on our 'Tracs.
It requires regular maintenance and cleaning, to avoid the "Rough Idle/Stalling Issues"!
P.S., Dave, You have WAY below average miles for your year of 'Trac!
May be time for a complete tune-up and maintenance, even though you do not have the
"100,000 Mile Interval" for your 'Trac, yet.
Also, an '02 'Trac with original tires may be facing a "Rubber Degredation" issue.
Regardless of miles, or wear patterns on the tires, after 5 or 6 years, the rubber compounds
can break down in the tires, causing all sorts of issues. The A.T.M.A. (American Tire
Manufacturers Association) recommends replacing the tires on a vehicle, regardless of
mileage, no longer than 6 years, depending on the weather conditions and climate in
your specific region of the country.