I got a trouble code 44 which is O2 sensor (lean exhaust), what does this mean? I was looking at symptoms in one of my cousins GM Marine TBI troubleshooting guides for engine bogging and the first thing it metions is the fuel filter. Now I have not changed this since I bought the truck last summer. I hope to change the filter this week and test the fuel presure. Anyone have any ideas what ight be going on??? Thank.