I have an 2003 disco I pick up for $1500. Ran a scan tool and came up with misfire codes besides spark plugs, wires and coil packs and o2 sensors what else should I replace?

 

I would start with plugs and wires and then see if it still misfires... then proceed to coils. O2 sensor codes will happen because of misfires, that doesn't indicate you need new sensors.

 

I had something similar. I replaced the spark plugs, wires, coils and o2 sensors. Turned out to be damaged block and blown head gasket. I’m just a noob but if those don’t fix it, get ready pull the heads. You can follow my rebuild thread to see what I’ve gotten myself into.

 

Could be so many reasons but I had same issue
the connector sometimes gets gummed up or wires not in properly
also if you have a bad fuel purge valve and sticks open you dump vapours and in my case it made engine run like crap and stinks like raw fuel or just rotten eggs and throws the bank 1 sensor 1 code

also a good smoke test to make sure you don’t have vacuum and exhaust leaks

 

I'd replace the coils, spark plug wires, and inspect the plugs. With all the work involved getting to the wires (after a few jobs it's not hard at all, but it is more difficult vs other vehicles out there). The wires can certainly get brittle and fail. How is the coolant level on this thing? IAC is probably locked up, and you can usually fix that with some carb/brake cleaner to free it up.

 

I changed the plugs, wires, and coils. I need to clear the codes and see if they come back. Changing the coils was not fun.