Not getting any hits on another thread, so I will re-post here:

1990 300te
California Car, 147,000 miles, 124.090 body, engine 103.983

Ok, I built Arthur's home brew code reader as a project with my 10-yr old son. It came out great and works like a charm. Tested the car, found tons of codes (most are probably old), cleared them one at a time and then drove some errands.

Upon return I got the following:

Pin 3 - 17 Oxygen sensor is shorted to positive or ground
Pin 14 - 3 TN/TD signal (RPM) interrupted

I have 2 questions:
Is pin 3 picking up the same Oxygen sensor fault that I get when I use the built-in diagnostic unit on my car that reports on the emission system?

What does the message on the Pin 14 fault mean?

Thanks in advance.