Bought a 2004 disco II on friday, ~90,500 miles. love it so far. plugged in my ultraguage and immediately got P0455 alarm, took it to a buddy with a scanner, it needs a new fuel tank filler neck. check engine light has since come on but no gas smell anywhere in or around the car whiel driving or idling. I ordered the new filler neck, but I have to drive about 100 miles this friday (50 there/50 home), and i won't be able to replace it in time. so far it's running fine but very worried about pushing it.

Any way to know how far it can handle before the filler neck is replaced? should i just try and borrow another car?

 

I would drive it. But I don't think you can pinpoint your problem to the filler neck with a scanner. You'd need something like smoke machine to determine what's leaking.
Please post your question in the Disco 2 section of this forum. You'll get more help there.