One problem related to engine has been reported for the 2007 Toyota Yaris. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Toyota Yaris based on all problems reported for the 2007 Yaris.
When the engine is running it will accelerate and decelerate by itself without me even touching the gas pedal. There doesn't seem to be any pattern as this happens randomly - when I am driving along, slowing down to turn a corner, when I am stopped, basically at any time. Dealership can't fix if they don't see the problem happening. Has happened randomly over the last 3 years at least 20 times. Last time was 1/21/10. No mats in vehicle for pedal to stick and pedal is not sticking. Happens when don't even touch pedal in neutral engine revs up.