Land Rover Repair: Service Engine Light and Mass Air Sensor, mass air sensor, throttle position sensor

Question
I've just had the service engine light illuminate and took my 99 disco II (64,000 miles) to a local repair shop for the first time (fed up waiting 2 weeks for a dealer appointment). The car was driving normally at the time and there was no noticeable deterioriation after the light came on. They're saying the fault code indicates a mass air sensor problem. They tried to charge $450 for the part (upon checking discovered that it can be had for as low as $125). Anyway, what known issues/symtoms exist concerning this part? I had the service engine light come on 3 weeks ago after the gas cap was not on straight. The light went off after a week while I was waiting for a dealer appointment. I cancelled the appointment thinking everything was ok. A mistake probably. I asked the repair shop to clean the contact terminals after reading another forum post (waiting to hear the result).

Thanks for taking the time to respond.

Neil

Answer
Hi Neil,

usually, MAF failures result in rough idling problems and loss of power.  You may be wiser to wait for you LR dealer on this one.  MAF are expensive anywhere and some owners will buy them from salvage yards.  They rarely fail but when they do - it's expensive.

Other areas to consider:

1. Crankshaft position sensor (might simply be a loose connection)
2. Stepper motor
3. Throttle position sensor
4. Mass Air Flow sensor (very expensive item)
5. Vacuum advance unit (may be ruptured)
6. Fuel Pressure Regulator
7. Throttle position sensor
8. Idle Air Valve
9. O2 sensors

Best of luck,

JohnMc