Help With Some Codes 1989 Corolla

Need a bit more information. How is the car running - running poorly, running OK, not running at all? Did these codes just pop up or were there for a while? What is the history of the vehicle - past maintenance?

Code 31 - Open circuit in VC signal or short circuit between VS and E2 when idle contacts are closed, affected systems are the airflow meter circuit or a bad ECM

Code 41 - Open or short circuit in throttle position sensor signal (VTA), affected systems are the throttle position circuit or a bad ECM

You'll need to get your hands on a wiring guide, need to have some basic tools and a good multimeter. Just a note, could be a bad sensor, or an issue with wiring. Sensor replacement if pretty straightforward, but wiring troubleshooting can be a nightmare.

Good example, a reference site to give you an idea on what to check (note this is for a Toyota 4Runner, so values could be different, sensor locations, and relevant wiring - but the diagnostic "procedure" would be the same)

TPS issue - http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

AFM issue - http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml