ok, so i've never owned a vehicle that did this, but...

Upon first starting when cold, my disco 2 misfires like crazy if i try to go anywhere, it throws the p0126 code and any and all cyliner misfire codes(i've reset several times and it's not the same every time, the cylinders misfire randomly). It does this even if i start it up whens its 50 plus degrees F. I have to start it and wait 5 minutes for it to warm up or it will misfire and be so weak I get stuck in the gutter, I understand the concept of optimal running temperature, but i've never had a vehicle that would malfunction if you just started it and drove off.

also sometimes it will be very weak getting on the freeway, start to backfire, and i have to move the gas pedal around to get it to run normal, and I get the 3rd gear ratio code. It tends to do this more if i've had a misfire recently(If I unplug the battery and clear the computer it does this less)

any ideas to help?