'93 Disco, 3.9L, been sitting for some time w/ stabilizer in fuel.
Starts right off, runs smoothly. Idle rises and falls slightly but steadily. No change when warm.
I've got a fault code 12, MAF sensor.

For a fault code 12, I should... "Refer to test 19, continuity test procedure."
My apologies if I've missed a FAQ, where can I find the "continuity test procedure".

 

Before replacing anything I would drive it for a tank or two of fresh gas.

 

Agreed, I'm way too cheap to swap parts until proven faulty. I wouldn't expect the built-in assumptions of EFI to work with funky fuel.

I am still curious about this diagnostic procedure for future reference, though.

 

I do not know what the test procedure is, sorry.