2002 Alero no acceleration

My 2002 Alero, 3.4L V6 auto - 128k miles abruptly started having problems last week. It all started after driving it on a grueling 350 mile trip (very hilly, 100+ degree temps, and a strong head wind) with no problems. Went to drive it the next day and found that it had no get up and go. I had to press the pedal very hard to get any kind of acceleration and it would hesitate before any power kicked in. In addition, it takes a lot more rpms (3-4000) before it shifts gears and shifts hard. The engine runs fine so it seemed more or less like a transmission problem. Had to reluctantly take it for the trip back home during which the SES light came on. In addition it now idles high (~1700rpm) and runs somewhat warmer than before. Took it to Autozone today and it came back with the following codes:

P0300 - Random Misfire
P0404 - EGR Flow
P0443 - Evap Emission

I'm not so sure anymore that this is a transmission issue and any information on the cause/solution of this problem would be greatly appreciated. Thanks!

Welcome to AF.

Have the CAT converter checked out. When they clog you get similar symptoms and the random misfire P0300 DTC. Also, makes the tranny look bad.

Thanks for the reply.

Took it to the shop today and they ran a back pressure test on the converter. It peaked out around 20 lbs so it was definitely clogged. Sure made it seem like the transmission was starting to go out though. Had a new converter installed and now the car runs like a champion. Thanks!