Hi Folks,

I have a 2006 L322 with the petrol AJ V8 4.4L that I just bought a month ago. I've been trying to go through the vehicle to check over everything and my OBD reader is showing 0V for both upstream O2 sensors. The downstream O2 sensors are reading in the 0.8-0.9V range on the highway and they will drop to 0.2V when coming to a stop light and then the voltage will climb back up to 0.8V when idling for about 30 seconds. I suppose this means the engine is getting stuck in open loop and running off a preset fueling map?

Long term fuel trims are in the 5 to 7% range. Short term fuel trims tick back and forth between -4 and +4%.

Fuel consumption seems high compared to government ratings, but outside of a bit of rpm hunting on startup and a low load around 1700rpm there are no adverse symptoms. Cleaning the throttle body is next on the to do list and I will do a smoke test to check for leaks in the intake system at that time.

Oh, and one more thing the previous owner had the Bank 2 upstream sensor replaced 20,000km ago.

Any thoughts on what the first things to investigate would be? I don't have any codes, so I suppose it isn't anything too serious, but with the price of gas being what it is anything to bring the fuel consumption into line is very welcome.