I bought a 2003 Pathfinder w/ 156k Thursday. On Saturday I was driving around with the kids and after a few hours my throttle response felt limited, almost like it became governed somehow. I could floor it and just barely accelerate. I made it home and noticed a slight burning smell that reminded of me of an old jeep I had when the catalytic converter went out. I checked the fault codes and only P0011 and P0021 came up. I know those codes are for cam sensors, I would not think they are related. I would have thought I would have received some sort of a fault code for the catalyst. After it cooled down I drove it again and it acted normal, no issues. I also noticed the mpg so far seems to be much worse than I would have assumed, which is also symptomatic of a bad cat.
Anyone else ever have similar issues?