Anyone have issues with this code? Coming up as the O2 sensor to the rear of the cat, or the cat itself. Runs fine when the light comes on, no operational issues. Have read about all kinds of tricks (paint thinner in the fuel, Sea Foam in the cat tube, anti-foul tubes to bolt the sensor into). I can erase the code, but its coming back on after about 100 miles. Truck only has 158,000 so Im thinking, Im running it hard now and blowing out some of the junk in the cat.