I've got a 98 disco 4.0l with 122,000 miles, it hasn't passed emission inspection yet even after induction cleaning, plugs, air filter, etc. I visited the local LR dealer(what a waste) to have them tell me it's burning coolant, needs an engine. Boy after 4,000 miles I haven't noticed any loss of coolant. Borrowed a scan tool that would connect to ecm and checked o2 sensors. Just as suspected, bank 1, sensor 1, flat line on graph at 1.02 volt. Ordered 4 new sesnors, waiting for them to come in. Also checked MAF reading which seems low to me. It's showing .01 lbs/? (I'm not a metrics fan) parked and maybe .05 at highway speeds uphill. Anyone have an idea that that reading should be?
I'm leaning toward ordering a new one so the ecm will provide the correct fuel for the air provided once the o2 sensors are giving the right info. I haven't had and codes in the ecm, but do have idle problems from being too high, just right and to stalling out. Fuel mileage varies from maybe 10 mpg(sub zero, lots of slow speeds) to just over 15 mpg, mostly 13.5 to 15. Not too bad but wouldn't mind a little more since it's mostly highway.

 

With a D1, if you use the proper MAF cleaner on a stone cold MAF, if there is a problem, you can usually correct the problem.
Have you also replaced your wires ?

 

the mafs reading should be in a weight per time measurement, and without knowing what time unit youre using, cant tell you if its good or bad. land rovers scanner uses kg/hour, and idle reading should be about 16 on a 4.0.

 

I had been reading it in english, lbs / ??, couldn't remember second half, but no matter if it was grams or lbs, it was at .01, to .05. In a quick training lesson on how to use this scan tool, the Nissan we hooked up to showed a much higher reading. Being a diesel tech, I normally read pressure from the MAP instead of volume. I just need a base reading of where it should be. If an engine requires 55 psi of fuel pressure to start, it may start with 40 psi but doesn't mean it runs right