Charlie - you're the man for this suggestion!

 

I am going to have a look at mine.

 

I thought I glimpsed yours in the famous video around the brake cleaner time... I'll have to find it again.

 

I just remember not catching fire. Thats a good memory for me.

 

Here's the final result of what was going on in this thread. Frequently with a Disco there is not one problem that generates a performance issue. In this case there were several problems that led to misfires, hesitation and all sorts of non-specific issues. Here's what I wound up doing:
- new O2 sensors, they were over recommended mileage and needed to be replaced anyway
- new MAF, believe it or not, it makes a huge difference
- loose ground wire was throwing all sorts of confusing codes and warning lights
- cleaned throttle body and checked all vacuum hoses, found split and repaired it
- replaced the battery under warranty - after several tests it showed a bad cell - buy a good battery, it's worth it, these vehicles draw a lot of electical power

All of the above I did myself and it got me to "'running OK" but not running right and still getting random codes. So, I but the bullet and went to a good mechanic. He replaced coils, wires and plugs, then rewired and replaced the knock sensors. I am right with no, codes, no hesitation and no warning lights. Total cost is about $1,500. There was not a single issue causing these problems, it was sort of everything and took quite a while to chase the problem and nail it down.

NOTE ABOUT KNOCK SENSORS: I have seen a lot of posts about the wiring of knock sensors and did some digging around. There was apparently advice out there at some point to disable them in order to improve gas mileage. That was bad advice and will eventually generate misfires while going up hills, which will translate into misfires any time the engine is under strain. The knock sensor retards timing to avoid preignition when under strain, without them the preignition will occur leading to other issues over time. My advice to you is to check the wiring and repair it it if someone monkeyed with it, and make sure that the engine is getting all of the inputs that the engineers designed into it.

Hope this thread is helpful to others!

 

Thanks for posting the solution! So few do that. for $1500 plus some parts and time I bet your rover will return the kindness for years to come.