This happens to me from time to time as well and I just spike the gas and it idles back down to normal. I have not sprung for the new tps yet due to $, but have adjusted it, and the adjustment did not solve the problem. My tps does have about 300,000 miles on it, and I am thinking this is probably the problem. Otherwise, check your throttle cable under the dash and on the end of it, there should be rubber spacers that wear out and could be hindering the proper operation of the throttle cable. I rigged mine to work just fine and if you need more info or pics, I would be happy to e-mail them to you just pm me. I don;t recall if the dashpot was brought up, but the other aforementioned are likely candidates in my experience as well.