2003 chevy silverado fouling o2 sensor after closed loop

[jaysonolson]

Hi every one I am having trouble figuring this one out. The problem I am having is weird. The truck runs fine at start up. Then after I drive for a few minutes the truck starts to run ruff and hesitates at acceleration. After driving for a few miles the o2 sensor fouls and is covered in black ash. The code reads as lean and low voltage on bank one sensor one. But the truck smells like fuel, un burnt fuel. I am thinking maybe a bad coil or a fuel injector leaking off. Anybody out there have this problem or know a check list to go down.

[jaysonolson]

Hi every one I am having trouble figuring this one out. The problem I am having is weird. The truck runs fine at start up. Then after I drive for a few minutes the truck starts to run ruff and hesitates at acceleration. After driving for a few miles the o2 sensor fouls and is covered in black ash. The code reads as lean and low voltage on bank one sensor one. But the truck smells like fuel, un burnt fuel. I am thinking maybe a bad coil or a fuel injector leaking off. Anybody out there have this problem or know a check list to go down.

So for anyone out there that has had this issue. I figured out the problem. It was a melted fuse for the fuel pump. I replaced o2 sensors, afm, fuel filter, map, every thing and all it was was the fuel pump fuse, just enough to let it run and not enough voltage to hold high rpm fuel pressure. The reason it ran rich at idle it was the lower fuel pressure allowing the fuel pass through the large marine injectors with more volume. Then less fuel to pass as the duty went up with less pressure. Causing a lean. I am glade i found it before a blown engine.