My 99 E430 CEL went off. I check the code and it was P0170. Based on searches in the Forum, this appears to "usually" be a problem with the MAF. I read I can try cleaning it, and if that doesn't work, shell out the $$ for a new one.

I was just curious what engine damage, performance problems, emission problems, or gas mileage degradation occurs if I drove around with a bad MAF for an extended time.

Also, what typcically causes this? Car has 108K on it, and I got a full tune up at about 106K...including the air/fuel filter and plugs.