No, the Speedometer is not acting up. I think I read somewhere that if the VSS was causing it, I could unplug the VSS and drive it. I know I would lose the speedometer while it's unplugged, but I could check if that is causing the "sputtering".

Thank you for the diagram showing the VSS. I may have 2 separate issues here, so these might come in handy if I am to replace the VSS

 

95% of all O2 codes on a Rover are tune up related, for you that means new spark plugs, spark plug wires, distributor cap and rotor.
That is a good place to start, it is a DIY even if you dont know much about anything.
Land Rover Parts & Rover Accessories From Atlantic British | Discovery, Range Rover, LR3, LR2, Defender, Freelander and Land Rover Series Parts & Accessories sells tune up kits, everything you need to do the job except the tools and time.
You can write down the list and then go buy the stuff locally at NAPA, AutoZone, etc. BUT do NOT use store brand plug wires.
You must use STI, Magnecore or Kingsborne plug wires as they seem to be the only ones that hold up.
The distributor is the round thingy in the front of the engine with 9 wires coming out of it.
It is held on by 2 straps, the rotor is inside the dizzy cap and it held on by 1 screw.
They cannot be put on backwards, they just wont fit.
There is a rubber vacuum line coming off of the vacuum advance on the bottom of the dizzy and it attaches to the little nipple (hehe) on top of the intake plenum (the thing that says 3.9 on it), that line must be attached to both.
So start with the tune up, clear the codes and see what comes back if any.
Also go to the tech section and read on the throttle body cleaning and do that before you do the tune up.

 

And yes you can unplug the VSS and drive, like you said, you will not have a speedo if you do.

 

Thank you Spike. Something to do this weekend. I appreciate the help, and will post an update.

 

Here's drawings for the O2 wiring, O2 has a heater and a sensor, the sensor side is the one with an arrow in it. Also, more info on the codes at Land Rover Troubleshooting: retrieving fault codes

IMHO check fuel pressure. If that's OK, then look at that VSS or some kind of vac leak, either a hose or MAF big hose, etc.

 

Also put a new fuel filter on it!

 

Ok - so this "sputtering" issue, caused by pressing the accelerator all the way down (or more than 1/2 way) has been going on all this time.

I was driving the other day - it was running a bit rough, I approached a stop off a freeway exit and it died. This has happened before, but I have always been able to just start it back up. Yesterday, I could not.

I now have a new cap & rotor, and new plugs and wires on it. Still nothing. It turns over just fine. I pump the accelerator - I smell no gas, so am sure it's not flooded.

Could it be the fuel filter completely preventing fuel from being delivered? Is there anything else I need to check. Remember - easy fixes - I live in an apartment and have limited tools and space to work on it. I have to get it running tomorrow so I can be at my first day of work at a new job Monday.

Thanks in advance.

 

On passenger side the fuel rail has a test valve, looks like a tire valve. When key is switched on, fuel pump should run for a few seconds. PSI at the test valve should be 32-34 PSI. If not, wiring, fuel pump, relay and fuse issues. Fuel filter is above and just forward of the right rear wheel.

If you are able to physically press accelerator all the way down, this should operate the throttle butteryfly valve to all the way open. You can see that if you take off air hose from the MAF sensor. If truck does not recoginze the position of the throttle valve, could certainly be a throttle position sensor (TPS). You may also need to clean your MAF sensor, when cold, with a product made for MAFs. The MAF tells th engine how much air is coming in, so it can computer the fuel mix. But my money is on the TPS.

 

Definitely check fuel pressure, I picked up this bad boy at harbor freight:
Fuel Pressure Tester & Fuel Injection Pump Tester

$20 and it works great. I used some thread tape on the fittings but just screwed the Schrader hose directly onto the fuel rail. As seen here:

 

Like these guys said, check for fuel pressure.