[thstone]

Driving with a bad MAF isn't good for an engine. How bad it is depends on how the MAF is failing and how much error is in the output signal.

For example, if the MAF output is simply varying (when it should be relatively constant, like at idle), then you'll get a poor idle and other uneven running conditions.

Or if the MAF output is biased "high" signalling that more air is entering the engine than really is entering the engine, then the engine will run rich, maybe foul the plugs and you may get an O2 sensor or DME beyond compensation limit CEL because the DME will try to compensate for the rich condition but there is only so much it can do.

Somewhat worse would be the opposite, where the MAF signal reads "low" and the engine runs lean which can be damaging to some engine components. Again, the DME will try to compensate for this lean condition but there is only so much it can do.

General advice is kind of obvious; if the MAF is bad, replace it as soon as practical.