Tuning up to improve my 95-850's mpg. When replacing the airfilter I tested the airbox thermo; never moved in the freezer. So curious me, I removed the airbox
to see how it works. My thermo failed such that it held the flapper door always
directing heated air to my intake. I remember RWD thread similar problem where this type failure, directing constant heated air to the air intake, would cause the airmass meter filament to burnout prematurely. Lotza $$$. I removed the complicated spring actuator and used a machine screw to hold the flap such that only fresh air is allowed in to my airbox. My mileage has improved. Maybe this silly thermo failure was the prblm all along. I'm told its only purpose is to hasten engine warmup but I notice little difference in warmup time.