Ok, I have a 2000 kia sephia. I have had it for almost 4 months. Recently, I had my alternator belt replaced. After that, my belts have always squeeled since then. I have yet to figure this one out. There was a small piece missing from my power steering tensioner. My driveaxles were bad, my brake pads, and I needed a new tire. Well, about 2 weeks ago, I drove my car one day and seemed to be starting to loose power going up hills or when I took off from a red light or stop sign. It seemed like it wasn't shifting gears correctly in low speeds. It wasn't all that bad, though. Well, that afternoon, my tire went flat & came off the rim and I left it sitting for 3 days. On the 3rd day, I jacked my car up, pulled the tire back on and blew it up. It did ok at first, but after a while, it started acting weird again. Shifting gears inccorrectly... loss of power going up hills, ect... it almost seemed like something wouldn't grab the next gear... like it wanted to, but just couldn't. So, I drove the car home and parked it for 4-5 days. Well yesturday the guy came and changed my driveaxles, brake pads, fuel filter, and added the tensioner parts. Well, my belt (or whatever it is) is still squeeling.... LOUD!!!!! I'm not clicking anymore and my brake pads are fine. When we tried cranking the car up after the reapirs, it took a LONG time!! He said it seemed like the gas wasn't flowing through the new filter quick enough. Also, my old battery needed a jump-off cause I accidently left my ignition on the whole time he was working. So, it crunk up, we drove it a second and it seemed fine. Later that night, I took off wide open... once I got onto the highway and needed to go from 35 miles an hour to 55, my car wouldn't pick up and go!! It like it was grabbing the next gear, it would rev up a little, but not alot, and continue going like 40 miles an hour. It kept doing this til I hit the gas station and filled up. When I left there, it wouldn't go over 20 miles an hour. My car would go, just not over 20.... my car sounded as if it were going in the next gear, and picking up speed, but really it just stayed at 20 miles an hour. Oh, and when I started up a hill, it would just slow down.... to a mere crawl... I would barely make it over. I made it to my boyfriend's parents and parked the car. I haven't had it tested cause I didn't make it into town... does anyone know what is going on with my car?? Oh yes, and right before I parked it, my check engine light and o/d lights started flashing. There is no smell or smoke or nothing....