If you have misfires on a disco it's almost certainly plugs and wires.

​​​​​​Run autolite iridium gapped to .032. Any wire set is OK. Check the stft and ltft and make sure they make sense. If they don't, run with mass airflow unplugged and check stft again. Check oxu sensor plugs for water and slime in them. It's not fuel, ignore all the "injector cleaner" stuff. Injector cleaner has not fixed a car in 20 years of me doing this.

 

Also these ecus suck at finding what cylinder is missing. Swapping wires is a terrible way to diagnose because it's a wasted spark setup. The voltage passes through 2 plug wires and 2 spark plugs. Just replace the set of wires, and replace the plugs with autolite iridium. Even if you just replaced them. Plugs and wires on disco 2 is 30k maintenance.

 

oxu sensor? Oxygen? Interesting to here the ecu isn't good at figuring out which cylinder is misfiring. Appreciate the insight I'll probably throw plugs and wires at it then.