2003 chevy silverado 2500 hd po300
 

I have a chevy Silverado whica got scanned and it showed 2 sensors on it and we replaced all four when it only showed 2 after doing so and erasing codes drove it a couple miles and check engine popped up again and ran scanner again and now it keeps showing 2 sensors and a new code po300 and now truck feels really weird any ideas truck felt better before all this any ideas please help thank you