I just bought this vehicle 6 months ago with 134k on it and body is in cherry condition. I have noticed that when I'm cruising at 75 mph with cruise control set, and come to a hill, it will shift down and rpm's will jump to 4k to 5k. I have since put 7000 miles on commuting back and forth to work. Yesterday I was bucking a hard wind. I would climb to around 70 mph and it would downshift and rpms would jump to 4k and I would actually lose speed down to 50 mph acting like tranny was slipping. I would let off accelerator and then I could slowly gain speed back up to 65-70 mph then it would do it again. Check engine light started flashing at one point. I have a Innova 3040 scan tool and the only code it would read is P0300. I realize I need to hook it up to a better scan tool, but I just wondering if someone has experienced these symptoms on their vehicle and what the problem might be before I start dumping money into it. Thanks for any help!