512TR o2 Sensor

Probably don't want to hear this...but try the search function on the upper left of the page, there are many threads on O2 sensors and proper test methods.

 

Have you verified that the ignition systems on both banks are firing? Always best to confirm that the ignitions are working (or not) before attacking the injection system IMO.

The simplest test (engine off, key off) is to unplug the single output wire from each O2 sensor and measure the resistance from the single output wire to ground. The O2 sensor's resistance is not constant with temperature (and I forget if it goes up or down with temperature), but, since you've got two, you can measure and compare them cold. An infinite resistance (greater than say 20 MOhm) is definitely bad as would be any great difference between the two (but, if one bank is dead, its O2 sensor won't warm up).

Have you also tried "jumping" the fuel pump relay sockets (engine off, key off) just to confirm that both fuel pumps are running (or at least that they're making a noise like they might be running )?

 

Yes I would check the fuel pumps. if one pump is off, the car will run very sluggishly, but will still run.

Is the engine note very subdued? that's another signal that it's running on one bank.

As to O2 testing, you really need to read the voltage on the thing, as it's connected to the system. Thing is, the car should still run without it being connected. And it runs fine at WOT without it. IF the ECU detects that the O2 is not providing the proper signal, it will take it out of the loop at idle and small throttle openings. It's only there to make good emmissions at idle and small throttle opening, oh and good fuel economy
Once you are on the gas, it makes little difference.

So the real question is, define sluggish? does it take 20 seconds to get to 60?

 

Here is what you can do to verify if the pumps are running.

pull each fuel pump relay, one at a time, and see what happens.
make sure you wait about 1 min before all the fuel is used up in the line.

If there is no change on one them, that is the one that isn't working.
Best to disconnect the idle control valves when doing this, that way, they don't try to compensate for the drop in idle, and might confuse the results.

Lets eliminate this for sure first

 

all's well