I did a tune up changed knock sensor which was bad spark plugs and the 2nd front o2 sensor. I now keep getting codes that all 3 o2 sensors are bad any have ideas to help solve the issue

 

Dont start flaming my grammar i am typing on my phone abd im just being quick with it

 

What are the exact codes? Do remember the original code? Ive heard the heating circuit involves a fuse that might be blown.
What exactly does "2nd front o2 sensor" mean?

Front Left = radiator
Front right = firewall
Rear = after cat (near shifter)

 

Now that you mention it i remeber the obd ii reader indicating heat sensor imma go check it out

 

It's telling you all 3 sensors are bad because you have blown the O2 sensor fuse. Replace it.

 

Thank you both i had blown a fuse. I didnt check it at first cause i didnt kno the o2 sensors even had a fuse. Thanks again.