2008 automatic Hyundai Accent gets stuck in 3rd gear and check engine light is on

Question

Hello I have a 2008 Hyundai Accent with automatic transmission and have been having issues with the car getting stuck in 3rd gear (the rpm goes way up and won't shift) and the check engine light is on... I had the oil changed today and had them run a scan and the codes P0717 (input speed sensor transmisson) and P0496 (Emissions high purge flow) came up. So what do I do now? Can I fix the problem myself?
The Hyundai dealership had sold me the following part:
Part #: J4651028000; Description: sleeve Assy speedometer driven gear; Location: 11B192613L
And the bolt to go with the part was: Part #: H1140306166K; Description: bolt-flang; Location: 11B193108A
I replaced these incorrectly at first as the same issues (described above) occurred but now the speedometer was not working. I eventually got the part in and the speedometer now works again but  the car still is getting stuck in third gear and the check engine light is on. I assume this part is not the issue... unless I still have the part put in incorrectly? Any ideas on what the two codes above would mean as far as resolving the issues would be greatly appreciated!