I have a 21 AT4 5.3 V8, and I've had the check engine come on showing the same code, however, it went away. I recently took a long trip, filled up at a local Walmart after I got back in town. Fast forward a few days and my truck has developed a bit of a shake when driving, along with a bit of a slip when coming to a stop, along with check engine light flickering some. Not sure if you have had the same symptom, but I am curious if I put a bad batch of gas in my truck. Was curious if you have experienced the same.