Hello there. I am hoping you can help me out. I own a 2001 Dodge Stratus, 50,450 miles. During a recent drive out of town (approx. 160 miles), I noticed a whirring noise, similar to a tornado siren, coming from underneath my vehicle. The noise sounds as if it's coming from the transmission or catalytic converter area and does not change whether the car is idle or is being driven. Well on the drive home, about an hour into the trip, my vehicle started to shimmy intermittently around the 70 MPH mark. Then it began to lose all acceleration power. I pulled over, checked all fluids - no leaks, everything full. I let it sit for 10 minutes or so and then it drove fine. 45 minutes later, same thing happened - the shimmy and dropping from 70 MPH to around 30. Pressing harder on the gas made no difference. Again, I pulled over, let it sit and then it drove ok. When I drove to work today, it seemed ok (but that's driving on regular roads, not the freeway). The noise from underneath was still present though. I've asked around and heard anything from " change the trans filter" to " have the trans flushed" to " the catalytic converter is bad". Any help would be VERY appreciated!