98 Disco I, 140k miles
For the last 6-8 months I have been trying to get the beast inspected and the test machine keeps coming up "not ready." It reads O2 sensor not ready and cat sensor not ready. Doesn't list specific codes, just says not ready. The check engine light is not on. Took it to the dealer and they replaced a fuse and said take it through the drive cycle and should be all set. Nope. No one seems to have a clue what is going on-including (or especially) the dealer. My regular mechanic says he has a friend with a Disco like mine who is having the exact same problem, so this doesn't sound totally unique so maybe some one here has run into this.
I should also add that the truck recently did produce a new code, misfire, and I had noticed it was running a bit rough lately. So the system does seem to be semi-alive.

Any suggestions would be appreciated.

 

You need to find someone who can do some live reading of your truck and see what is not working.

 

I assume "live reading" goes beyond plugging a OBE II reader in? Is this not something the dealer should have done?

 

i would go back to the mechanic and say you told me it would be OK and it is not. Don't pay another $120 diagnostic fee just have them figure it out.

 

Just out of curiosity, When is the last time you changed your thermostat? If it doesn't think the truck is up to temp, it won't read the systems. They will not read ready until the engine is warm... gauge may even read up but on the low side. Actual temps and what the gauge reads are very different...

Just a thought