So my Camry was... "gifted" to me right at the age that sensors and the like would be failing in a chain, one after the other. It's been getting really bad mileage (about 16.6mpg) and I've begun cleaning what I can. Pulled the MAF sensor out, cleaned it. While it was out, I took a good look at the rest of the air system- The TPS was unplugged. Plugged it back in and my idle began surging, quickly. Quick up and down, but closer to a drop and comeback. It'll sit at normal, drop to about 400, and come back. Sometimes this happens just at idle, sometimes it only happens when I'm on the brakes. When it only happens when I'm on the brakes, I must be moving or it doesn't happen. All I can think of that would cause this, though, is the TPS- After all, that's the only thing that changed... And then I had the problem. Why would the brakes cause a surging idle just because I plugged in the TPS? Anyway, I might go to a u-pull-it style junkyard this weekend and pick up a new TPS and a new MAF. The O2 sensor is new and I've checked all of the coolant temp sensors- they're all in spec. Can only think of maybe the TPS and MAF causing my bad mileage.

Ideas? Do you think I'm right with this one?

Edit: I forgot to specify. This is a 1991 Camry 4-cylinder (3S-FE)