i put my new maf in yesterday and all i can say is wow. it feels like a brand new car. i bought my car used a year ago and it now has about 50k miles on the odometer. it has never felt this strong. the exhaust even seems to have a deeper tone (is that possible?). if you think you need one and have been considering putting a new one in i'd go ahead and order one. took about five minutes and made a tremendous difference. thanks to everyone for the help in diagnosing the problem.

 

Re the exhaust note, might be the same phenomena of a car seeming to run better after it's washed ;-)