I have a 3.0L Mazda6S automatic, and had transmission issues in 2006 after I purchased the car. Fortunately it was still under warranty and I had the transmission replaced at no charge.

Recently the CEL came on and the car was having a very delayed response. I took it into the dealership, and their diagnosis found that the air intake boot was split and a throttle position sensor failure. So the throttle body was replaced and they did a fuel induction service. I picked it up on Friday, and they told me to come back Monday so they could put the air hose on (it hadn't come in yet), but it was safe to drive until then.

So it drives okay on the way home, except the transmission bucks twice. Kinda like shift shock, where there is a delayed response getting it into gear and it kicks hard. Then later that night it keeps doing that and the Check Engine Light comes back on! So I figured I would get this taken care of Monday when I take it back in for the air hose. I don't drive it Saturday. Today (Sunday) I tried to leave but it was acting up to where I don't feel comfortable driving it. It wasn't shifting right, it would shift really quick and stay around 2000 RPMs.

What could be the problem now? I already paid them a LOT of money to fix my car, and now I'm having transmission problems suddenly? Could this have anything to do with not having the new air hose on yet? What should I expect when I take it back to them tomorrow? Is it safe to drive there?