O2 Sensors - OBDII P0146 & P0147

'97 Isuzu Rodeo 3.2L - 128000 miles My check engine light came on about 2 weeks ago, so I took it to AutoZone for a free OBDII test and I got the following errors:
P0146 HO2S Insufficient Activity Bank 1 Sensor 3 P0147 HO2S Heater Circuit Bank 1 Sensor 3
Now I thought that this was for the O2 sensors malfunctioning. There are three O2 sensors on my Rodeo. Starting from the engine towards the back of the vehicle, I replaced the first sensor, left the second, and replaced the third. After replacing these i disconnected the battery for at least a minute but the Check engine light keeps coming on. Any help?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.