new 02 sensor with a no signal code . what may be the issue ?

code stated no signal from 02 sensor . mileage is same as always and runs great . stared at about 100,000 miles

Ok, the message displayed by the code reader is subjective because it is proprietary to the manufacturer of that code reader. I really need to know the code in order to offer any troubleshooting tips. It should be five digits, beginning with the letter 'P', followed by 4 numbers. ex. P1234