Overdrive issues after timing belt change.

[TheThunderRunner]

So I got my timing belt done about two weeks ago. I had a 4 hour drive back home after getting it done and the whole way home on the freeway (cruise control for half of it) everytime I was on even a slight incline the engine would shift to overdrive (nearly 4k rpm) and it burned gas like crazy coming home (I got 17 going to get the belt done and 12 coming home, measured manually). It still idles high (about 1200 rpm) and when I put my foot on the pedal to really accelerate it hesitates for about a second or two and then shifts way into overdrive and then back up. It feels like there is now no middle ground between downshifting once and going to overdrive. Among these issues it threw a check engine light that showed multiple cylinder misfires. I disconnected the battery and reset everything and a week later I'm still having issues (with the exception of no more check engine lights). Mechanic said it may be the MAF sensor. Any other suggestions?

 

[supersaiyan96]

Those symptoms sound like you have a vacuum leak somewhere.

 

[damthemainstream]

Overdrive is your highest (least RPM) gear. What you're describing is the transmission downshifting into a lower gear. It sounds like the shop who did your work may have left something unplugged.

Edit: given that you had multiple cylinder misfires, I almost wonder if they have the timing off by a tooth on one cam.

 

[djkurious]

From past experience of changing timing belts it seems the belt is off a tooth or two.