I'm not a mechanic, but I'm pretty sure you have one O2 sensor just before the catalytic converter and one after. The first checks the function of, and regulates, your fuel control unit, and the second checks the efficiency of your catalytic converter. My #1 O2 sensor is screwed into the exhaust pipe about a foot or two before the converter and kind of looks like a spark plug.
On a 2003 Isuzu the O2 sensor is on the driver side of the engine compartment about a foot down from where the exhaust pipe comes out of the header. Just follow the exhaust pipe out of the engine and you will see it. It looks like a spark plug sticking out. It's pretty easy to disconnect the wires, unscrew it and replace it. You will need a 7/8" open end wrench to unscrew it. Good luck. * 1999 Oldsmobile Aurora's actually have 4 O2 sensors, 1 on each header and 1 before, and 1 after the catalytic converter...
the bank 2 is on the driver side i got this info from an Isuzu mechanic
Not a valid code. If it's P0134 the it would be oxygen sensor bank 1 sensor 1, no activity detected.
Not a valid code number, check again. If it's P0131 then it would be a oxygen sensor on bank 1 sensor 1, low voltage.
Passenger side is bank 1 & Driver side is bank 2
Trouble code P0171 means: System Too Lean (Bank 1)
Bank 1 is the side that cylinder 1 is on, sensor 1 is downstream and sensor 2 is upstream
02 Sensor Insufficient Switching Bank 1 Sensor 1
Oxygen sensor heater malfunction (cylinder bank #2, sensor #1)
Driver side
Drivers side behind the convertor.
If this is a 6VD1 engine, the camshaft position sensor will be located on the very back of the left bank head (on the inside, under the intake manifold). The easiest way to have it replaced or removed is to take off the intake manifold. The sensor is only secured with one 10mm bolt but it is a frustrating thing to put it back on with the intake installed, unless you have very slim hands.
If the Trooper has the 3.5L v6, there are 4 SO2 sensors. There are two banks right and left, or bank 1 and bank 2 respectively. Then there is a sensor upstream from the catalytic converter on each bank (sensor 1) , and one down stream (sensor 2).Hope this helps/