I have this problem with both my, and my daughter's Corollas. Hers is a '94, and mine an '04. The symptom is a sticky accelerator pedal...meaning, occasionally the pedal sticks at idle and you have to keep pushing on it until it finally lets go, then the car lurches forward. This is not a problem on dry pavement, but on snow it causes the tires to spin. I've had the '94 to my mechanic for this problem and he said it's caused by a build-up of tarnish inside the throttle body, which has to be disassembled and cleaned. My '04 just started doing this, but so far it hasn't gotten nearly as bad as it has on my daughters '94. My question is, is there a fuel system cleaner (like BG or STP or something like that) that will get rid of this tarnish, and if so, will a one time application get rid of it?