I think I need a final stage resistor because when I have the interior fan at full power, it is only blowing out air like its at 1/2 way. Is removal and installation an PITA . Mileage is at 128,xxx. By next weekend, I am going to order the radiator, expansion tank, water pump and fan clutch as I am getting near the 150K mile mark. I might as well get it out of the way now just before I hit 130K. I changed the belts, hoses and thermstat at 110K miles. Should I buy all four 02 sensors since they haven't been changed when I purchased the car with 79,944 miles or wait till the check engine light comes on? Gas mileage is great, thanks to the tune up a while ago and the car has been running fine.