I have a VE Calais 07
Where are the 02 sensors located? I am told if I disconnect them the car will go into limp mode it will run but I can find out if the sensors are sending information back to the ECU that reduce my fuel to the engine. My auto sparky told me my number one fuel injector on bank 2 was wide open flooding the engine I changed them today but did not resolve the issue.We don't know if the 02 sensor is the problem or the ECU is the trouble?
There are 2 upstream of the catalytic converters -one on each side. These are visible from the engine bay near the exhaust manifold.
These two control the air / fuel ratio so I would focus on them and on a live data scan, these should be constantly flipping between rich and lean (high v and low v). You can also remove a vacuum line and see how the 02 sensors react during live scan
There are another 2 down stream of the catalytic converters. These monitor the effectiveness of the catalytic converters. On that note though these should also be checked during live data scan and should remain steady high voltage. They should not flip between high and low voltage .
Some other points,
1) has the whole exhaust system including catalytic converters been checked for bends or unwanted restrictions like some damage
2) on my LLT engine there is a fuel pressure sensor on the fuel rail. If your car has one, has this been checked?
3) The fuel pump unit has a fuel pressure regulator.. has this been checked / replaced at the same time as the fuel pump?
4) how's the carbon in the car? Quick check by opening the oil cap and having a look at the cam for carbon. Can be properly checked with an inspection camera by removing the spark plugs
5) has a cylinder compression / leak down test been completed?
6) has the MAF sensor been checked?
