Help finding replacement sensors

[SeafoodDisco]

Hey guys, I am pretty new to vehicle repair, and this will be my first time purchasing replacement parts for a vehicle. My 2008 Aveo has engine codes P0502 and P2A01, and it looks like I will need a replacement O2 sensor and speed sensor. Do you guys have any idea on what sensors I should get/where I should get them. Should I go for OEM parts or not? As I stated, I am pretty new to this, and any help would be appreciated.

[avguy]

Before hanging on any parts, I suggest you check the integrity of all related wiring and connectors. Next you could check the resistance of the downstream O2 heated circuit. If that's in spec, you might remove, check, clean, and reinstall the sensor. If none of that fixes the issue, then replace the sensor.

AFA the P0502, that's a correlation code, and doesn't (by itself) positively ID the speed sensor as the culprit. One of the possibilities is some issue related to the wheels. Have the wheels been replaced by a non-standard size, or have the wheels or axles possibly been damaged recently?