Had the guys at Autozone pull the codes, then reset the light with a neg battery cable pull. I got:
P0300 Random Misfire
P0301 Cyl1 Misfire
P0171 O2 Sensor Too Lean Bank A
P0172 O2 Sensor Too Rich Bank A
P1171 Oxygen Sensor System Too Lean Fault Banks A & B
P1171 Not sure on this one

The light relit after 15 miles of driving, about 25 minutes or so. I'll get the codes pulled again tomorrow after driving to/from work to see what is in there now. Pretty sure the truck had 87 octane gas in it when I got it, luckily the fuel was low, so the fill up of 93 should have corrected that.

Any ideas with the particular combo I have? I'm thinking plugs/wires (will be covered in 60k service in the next week or so) and O2 sensors. Will wait to see what codes set before I look into 2-4 new O2 sensors. BTW, what size wrench are LR Disco II O2 sensors? Last time I replaced one (not on a LR), it seemed a large metric size like 23-24mm.

 

There are 2 different lights on the DI dash, a amber "check engine" light and a red "service engine soon" light.
Yes you can reset the red one yourself, it is a emissions service reminder.
www.discoweb.org, tech section, "how to reset service engine soon light on a DI"
A DI is a DI is a DI, so all parts from a DI will fit another DI.
The diff's are the same for all years upto and including the '04.
That means a diff from a '89 Disco will fit a '04 and vise versa.
Start with new plugs and wires, use Magnecor plug wires from www.ApexPerformance.net.
I use Iridium plugs, you can use whatever you want.
I get my used parts from here and I highly recommend these guys.
www.autosportsunlimited.com
New parts from local auto parts stores or www.atlanticbritish.com
Lots of pics at www.roverlandparts.com.
www.roversnorth.com has a great catalog/magazine, get on their mailing list.

 

Yeah, gonna do plugs and wires soon. I have a bad misfire when the engine is cold, sounds like popping in the exhaust.

 

Check out Rover Owners' Assoc of Virginia at www.ROAV.org

 

The very first thing you want to do is run a can of seafoam through the induction. This will reduce the carbon buildup in the engine, and with bad plugs and O2 sensors, you are not going to hurt anything.

After the seafoam, replace your O2 sensors. Do all 4 at once. You can rent the O2 wrench from just about any parts store, and the rental fee is usually a returnable deposit.

After replacing the O2 sensors, replace the plugs with regular copper Champion plugs. Make sure you use 8mm Magnacore wires though. Our trucks get finicky with others.

Good luck.

 

Thanks. I thought the oil needed to be changed after the Seafoam? I just changed it with Mobil! two days ago.