I noticed scan tool showed friends MAF sensor flow at 0.24 and never changed (it had a wire that was melted through so system was using that value like it was unhooked?). Was curious if the car running that way would damaged the converter? Would it make the car run lean?

 

It would not run right, that is for sure. That is the baseline voltage out of a hot wire type MAF sensor. The GM MAF sensors are cold wire sensors and have an output in kHz (frequency).