DON'T UNDERSTAND CODES & EXPLANATIONS H E L P

I have a 1996 Chev. 1/2 ton Z-71 with about 110, 000 miles. The truck was running fine, but developed an idling problem. I have replaced the O2 sensors, plug wires, plugs but to no avail.
I had the codes read and they are as follows: po 172 po 175 po 300 I do realize the first 2 mean the right and left bank are running to rich. The third code means random misfire at idle.
I am stationed aboard the USS Nimitz in San Diego and have a very limited budget. Please e-mail me ANY suggestions as I do not have access to Agent often. My e-mail address is:
snipped-for-privacy@yahoo.com
Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.