1995 Honda Accord Check Engine light and malfunctioning odo

Hello

I had a check engine light come on this past year. When I did the reading, the computer code said it was the throttle body sensor. Also the rpm odometer was bouncing around or not moving sometimes so I gathered that was the issue.

I recently had a a friend replace the throttle body on my 1995 Honda Accord LX V6 sedan. He reset the computer and it seemed fine. The check engine light was off and the odometer idle was back to normal. My car's performance was optimal.

Then about a month later the check engine light came on again and the rpm odometer reading was back to the way it was before however the drive performance is still good.

My friend said it could be a result of not having the right factory equipment to calibrate the throttle body and get it back to spec. He was able to replace the throttle body and set the voltage to the recommended idle standard but he doesn't have Honda equipment to be sure.

Do I have to go to a dealer or go to a repair shop with the proper equipment to get rid of the check engine light and restore the rpm odometer?

Or is this something entirely new?

Thanks in advance
Eugene