I bought a delphi ES20166 front 02 sensor from my local parts store a few months ago. I just got the p1176 a couple times, been searching and most people think that code can be a bad front or rear 02 sensor. I also looked up the part number and some sites show the deplhi as a rear sensor and some as a front sensor. I'm running a little rich but I don't think its enough to be beyond the control limit. Is it possible that the sensor I got just has a lower limit before it throws a code? Im apr stage3 and have the test pipe tune so it shouldn't have anything to do with the rear sensor, but I did also get a code for the cruise ctrl stalk with the first p1176 so maybe the chip is starting to take a crap?