Do I need a new O2 sensor or is it something else??? - Calling all you Sierra or Siverado guys

Whats up everyone?  I have gotten 2 different codes on my 2001 Sierra today.  The SES light came on this morning right after I pulled out of the driveway, and I checked the code later on, and I got P0155(O2 sensor heater circuit malfunction bank 2 sensor 1), I cleared it out thinking it was a fluke and waited to see if it came back, well the SES light came back, only this time with code P1153 (O2 sensor heatercircuit high voltage bank 2 sensor 1).  I've also from time to time noticed a STONGER THAN USUAL  smell of exhaust lingering in the driveway when I get home, almost smells rich, just potent smelling.  Also right before the light both times, the truck seems to hesitate at take off from a stop sign, or redlight.  I'm gonna guess I need an O2 sensor, but just want some insight from others before I drop a bill on an O2 sensor.
 
 
Laterz
Mat

I would say you need a new oxygen sensor for sure

yes you need a new O2 sensor

I had that same prob on my 97 chevy extended cab.  checked both bank o2 sensors and only had to change out bank one which i think is the drivers side cant remember.  Make sure that u check both if you two.

If you are not convinced and want to be sure. Just swap sensor with another. But that's just what I would do.   Good luck.

plain and simple new o2 sensor