I meant any problems with (mass air flow censor)?

I got in my car tonight to go home from a friend house and my ABS light was on.
I drove the car today with no problems and no light. I stayed at my friends
house for about 2 hours and went to drive home and the light was on? any idea
what this could be? what should I do to get this ...

I have no experience with front wheel drive cars, but if this were a rear
wheel drive the problem would be obvious..wheel bearings. Specifically,
the front end of my Max has a grinding whirring coming from the front
wheels when moving. Is this a possibility? Odo only has 75k, seems ...

i have a 93 nissan maxima se.  the sunroof tilts just fine but no longer
slides.  for a while it would move about one inch and then stop but now it
wont slide open at all.  is there some way to open the roof manually to be
able to check it out? or what could be the problem?

My front end (driver's side) makes a metalling popping sound when going over
sharp bumps, i.e., seems to happen when the suspension changes direction
quickly, like a bumpy road or a 20 mph speed bump.
I once had a Honda with a bad ball joint that made much the same noise, so I

Any futher ideas/leads would be much appreciated...
I have followed Trends on similar problem (No Crank), and followed the
Haynes Manuel.  I must be overlooking something. I've copied this list
from a different post:

I need to replace my entire exhaust, including muffler and front pipe.
Estimate is $1,200CDN from the dealer.  Anyone know of a good online used
parts dealer that can help me cut this cost in half?

My son has a 92 Maxiima SE.  Lately the windows won't go all the way up
and he has to push them up by hand to get them closed.  While driving
they will fall down as well or they will just fall down without
driving.  What is the problem and how to fix without spending a fortune?