Wiring Harness for O2 Sensors
 

I believe this may be my problem with my check engine light because I've replaced both sensors (twice) & I went to the dealer & the codes I'm getting are p0141, p0131, & p0135 all electrical related.

Does anyone have any experience replacing this & how much it would cost? BTW it's for a 07 MC LS 3.5 Flex Fuel Engine

Did you replace the sensors with AC Delco units? Are the replacement sensors of the heated variety? These vehicles can be picky when it comes to their sensors and a lot of times replacing them with a brand other than AC Delco will set the CEL because the sensor isn't within the parameters of the original unit.

What brand sensors did you use? They seem to be related to the heating element. Did you get a heated sensor?

Also make sure you don't have any intake leaks, or anything causing you to run too rich, that could affect your sensors too

*edit* had tab open for some time, and see that Mike above me said almost the same thing lol

Yea I just put heated AC Delco sensors on there, but I do have a small oil leak do you think that could be causing it to run lean, because i do have hesitation while driving still

Finally got my problem solved turns out I had a loose connection to my fuse box. Hopes this helps someone in the future.