All,

I have 98 EB w/ 5.4L that has developed a misfire. Noticeable rough idle and the scanner revealed:

P0156 - Bank 2 Sensor 2 02 Sensor Circuit Malfunction
P0305 - #5 Misfire
P0174 - Bank 2 System Lean

I check elec connections to #5 Coil and #5 Fuel Injector and they are all good. Went and bought a new coil and spark plug. Replaced both, same condition. What else could it be? Fuel Injector?

I can see why the 02 error would occur as I am sure the temp is hotter than it should be in the exhaust, and I assume that could lead to the lean condition. I disconnected the battery when I was replacing the parts, so the CE light is not illuminated when I test drove it. It is still noticeably misfiring, but maybe not quite as bad. I don't want to drive it any more as I don't want to damage the Catalytic Convertor or 02 sensors. It is going to the shop on Monday morning, but if someone has something else to try, I will try that first.

Thanks,

Ron

 

Welcome, this is a great site for general information, but your question is much more engine related. You might want to head over to the 4.6L and 5.4L engine forum and ask the question/search for information.

Good Luck.