Fusion11Your experience and mine sounds similar.
I have a 2010 Ford Fusion right before 37k miles and prior to receiving the letter when sitting at traffic lights sometimes the idle would drop run rough for a less than a second then come back up to normal but the light didnt come on thinking maybe some bad gas I changed stations and put in super same problems were experienced. Just as I got concerned the letter showed up and I took it to the dealership and they did the code update and I got an oil change while there.
Not even a week later I backed out of the driveway and the car started to slow studder with power like going from half power to 50hp but a smooth drop and increase it lasted about 10 seconds then was gone but then shortly after I made a right on red and it dropped luckily i had lots of room to get into the lane but if I were crossing in front of oncomming traffic I would have caused some brake lights or worse. Prior to this the shift points on the transmission had been unusual again. Not like it was missing shifts but just not shifting at the right points for a smooth ride for the way I was applying gas. Never did the check engine light come on or the car go into limp mode but really surprised the check engine light didnt come on. These were really noticable performance drops. I didnt have the power on tap like it should have and took it immediatly to the dealership when this time they replaced the throttle body and said they reprogrammed the transmission which it has been in for before.
Since then Im going to say its much more robust, idles better, shifts smooth, and feels like a new car. I too suspect gas mileage may be up but traffic is hit or miss to tell for sure but I will say Ive hit a lot more traffic recently and gas milage didnt go down. The change is significant making me think the performance was slowly degrading where I didnt notice because of the gradual decline. I didnt check to see if I have the new or old part now all this just recently happened but I am concerned that the performance drops I had didnt cause the check engine light to come on. Whatever the programming is behind that seems a lot looser than it should be I certainly believe all my past cars would have thrown a check engine light. Like I said had I been turning across traffic and suffered the same performance drop I experience this could have been worse.
This is my first Ford so far Im on the fence as far as Ford reliability and Service over other american car makes.
