Yeah, that's low, even for a Sequoia. I feel your pain -- I bought a 2002 back in March, and my gas mileage has steadily dropped from 13.5 to 11.5 MPG (all in-town, no towing). The current tank is well on its way to being 10 MPG (halfway down, only 107 miles on the tank). Still trying to troubleshoot *why* without resorting to just shotgunning parts. At the moment, I miss my Taco like you miss your 4Runner
.
With mileage like yours, I'd suspect something in the fuel control setup more than just subtle stuff like oil or tire inflation. Unless you've got 40 pounds of lead in your right foot. Any chance you can hook up a laptop-based OBD scanner to see what your sensor readings are? I'd love to have someone to compare notes with...