I have a 2008 z71 with 78000 miles, I have a edge evolution tuner, K&N air kit, and dual side exit flowmast exhaust. about 2 weeks after getting the exhaust installed, I am getting p0060, and p0160 cel. I have gone through 3 AC delco sensors, checked all fuses, checked all wires and still cant figure it out. no headers, cats still stock, no other mods. I have looked all over the internet, other forums etc.. no one I have found can diagnose this. Im to the point that im thinking its the ecm.. or maybe it needs a custom tune because of the minor mods??? usually if the cats are still there, you shouldnt have to tune out the rear 02 sensors, right?? Any help I would appreciate.
Thanks

 

BTW I know what the codes mean, my edge has the reader..

 

Look at the wires for the passenger side downstream O2 sensor. It could have a break somewhere in the wire.

 

Besides breaking down the whole bundle of wires and following everyone of them, i have already checked.. today I switched the rear sensors to see if it will throw another code.. anyone else have input?