Hello guys. Recently I got this 03 Cavalier automatic and a couple days ago the check engine light came in. I scanned and got code P0480. The car's running fine and not overheating at all. The engine feels pretty smooth and strong. I was told there may be something wrong with the cooling fan relay, so I replaced it and everything is the same, and still got the code after reseting the computer.
Another issue I'm having sometimes is that sometimes my car hesitates a bit when shifting from 1-2 and 2-3. The car revs a little higher than it should but eventually shifts into gear. The funny thing here is that when this shifting issues happen, the speedometer stops marking. When it shifts, the speedometer is up and running again. I was also told the speed sensor may be faulty so I replaced it with a new one. The car is better, but I'm still getting shifting issues once in a while.
Can you please let me know your thoughts about these issues. Thanks and have a great day!