Just picked up a 2000 DiscoII with 167k a week ago and am THRILLED with my purchase! My only issue is the SES light being on and showing 4 codes.
P0130 being 02 sensor circuit malfunction bank 1
P0150 being 02 sensor circuit malfunction bank 2
P0171 being system too lean bank 1
and P0327 being knock sensor circuit low
From what I've read running low octane fuel on these is something that should not be done. I've gone through 2 tanks of premium fuel with a bottle of seafoam in each hoping to clean up some internals. Seem's as though these are all related somehow. Is this a common problem? Any solutions or thoughts? Thank you in advance.

 

Would look at the knock sensor to be sure wiring not frazzled or loose. Knock sensor values used to force timing adaptions. Would look at new plugs and wires, O2s and misfires can be related to that, but with high miles may also be time for O2s. In our tech section is a 60K high miles service list you can work thru. By now you have heard of the RAVE service manual set, full download link for free below. Here's a page on the knock, and pix of location, shows you what can be had in the manual. One on each side. Bolt needs to be snug, it can't be finger tight.

 

Great, thanks for the info. Lets see what can be had after work!