CEL came on during last drive on highway. While arriving home I began noticing a raw gas smell coming in from vents. I suspected that I had another loose clamp on a fuel line (as was the culprit earlier this fall when the weather turned colder and I had a gas smell in the interior) and indeed I did. The clamps were a bit tough to get to this time, but I was able to fix the leak. Is it possible that the fuel leak was responsible for the CEL coming on? The codes suggest a lean mix (P0171 and P0174) and so it seems logical to me. If not, any suggestions about things to worry about? I checked the PCV and it seems to function well. Otherwise all seems normal.